有大佬帮忙看一下这个死锁怎么形成的吗

Question

从下往上看
按道理主键+RR不会形成死锁啊，还有update也有s锁的吗？

InnoDB: *** WE ROLL BACK TRANSACTION (1)
InnoDB: *** (2) WAITING FOR THIS LOCK TO BE GRANTED:
InnoDB: *** (2) HOLDS THE LOCK(S):
InnoDB: *** (2) TRANSACTION:
InnoDB: 
InnoDB: *** (1) WAITING FOR THIS LOCK TO BE GRANTED:
InnoDB: Transactions deadlock detected, dumping detailed information.
update `examinees` set `token` = 'eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJpc3MiOiJodHRwOlwvXC9leGFtLmNvZGVwa3UuY29tXC9hcGlcL2V4YW1pbmVlXC9sb2dpbiIsImlhdCI6MTU3NjM3MjE4MCwiZXhwIjoxNjEyMzcyMTgwLCJuYmYiOjE1NzYzNzIxODAsImp0aSI6Im15TGZ6NmhqVFJzYTNjb1EiLCJzdWIiOjg4NCwicHJ2IjoiNDY3MGJjYmM4YzU5NTJjZTdmN2ExZjQ4OTliOTU0YzU1YjU2NDMyZCJ9.pIIe2xY-eh_3_HhUOURdj325sq9Od1koOVPlRKZ6hXM', `login_count` = 7, `last_login_at` = '2019-12-15 09:09:40', `examinees`.`updated_at` = '2019-12-15 09:09:40' where `id` = 884
 1: len 6; hex 0000003d236f; asc    =#o;;
 5: len 15; hex 38353836343036304071712e636f6d; asc 85864060@qq.com;;
 14: len 30; hex 68747470733a2f2f6578616d2d313235333338363431342e66696c652e6d; asc https://exam-1253386414.file.m; (total 92 bytes);
 10: len 18; hex 343431333233323030383130303333343131; asc 441323200810033411;;
 14: len 30; hex 68747470733a2f2f6578616d2d313235333338363431342e66696c652e6d; asc https://exam-1253386414.file.m; (total 92 bytes);
RECORD LOCKS space id 301 page no 83 n bits 88 index PRIMARY of table `exam`.`examinees` trx id 4006767 lock_mode X locks rec but not gap waiting
Record lock, heap no 12 PHYSICAL RECORD: n_fields 27; compact format; info bits 0
 3: len 9; hex e69d8ee59bbde7909b; asc          ;;
 25: len 4; hex 5d68cbfc; asc ]h  ;;
 18: len 24; hex e883a1e88081e5b888e280ad203135333237323433333934; asc              15327243394;;
 7: len 30; hex 24327924313024526e656676315a48716755427072383455456c71732e45; asc $2y$10$Rnefv1ZHqgUBpr84UElqs.E; (total 60 bytes);
mysql tables in use 1, locked 1
LOCK WAIT 19 lock struct(s), heap size 1136, 8 row lock(s), undo log entries 224
 3: len 6; hex e69cb1e888aa; asc       ;;
 7: len 30; hex 243279243130247756783376524c2e38756457306945644f6e5061734f53; asc $2y$10$wVx3vRL.8udW0iEdOnPasOS; (total 60 bytes);
*** (1) TRANSACTION:
 0: len 4; hex 00000374; asc    t;;
 13: len 0; hex ; asc ;;
 22: len 4; hex 00000008; asc     ;;
 23: len 4; hex 5df58817; asc ]   ;;
Record lock, heap no 19 PHYSICAL RECORD: n_fields 27; compact format; info bits 0
 8: len 1; hex 01; asc  ;;
 18: len 24; hex e883a1e88081e5b888e280ad203135333237323433333934; asc              15327243394;;
 11: len 1; hex 81; asc  ;;
 13: len 0; hex ; asc ;;
 16: len 1; hex 81; asc  ;;
 20: len 4; hex 00000000; asc     ;;
 22: len 4; hex 00000004; asc     ;;
 24: SQL NULL;
 6: len 11; hex 3133383032353838323832; asc 13802588282;;
 21: len 30; hex 65794a30655841694f694a4b563151694c434a68624763694f694a49557a; asc eyJ0eXAiOiJKV1QiLCJhbGciOiJIUz; (total 337 bytes);
 24: SQL NULL;
TRANSACTION 4006767, ACTIVE 1426 sec starting index read
 19: len 4; hex 00000013; asc     ;;
RECORD LOCKS space id 301 page no 28 n bits 88 index PRIMARY of table `exam`.`examinees` trx id 4005686 lock_mode X locks rec but not gap waiting
Record lock, heap no 19 PHYSICAL RECORD: n_fields 27; compact format; info bits 0
MySQL thread id 10516222, OS thread handle 139667263854336, query id 300969200 ***.190 exam updating
 10: len 18; hex 343431333233323030383130303333343131; asc 441323200810033411;;
 11: len 1; hex 81; asc  ;;
 12: len 4; hex 00000000; asc     ;;
 16: len 1; hex 81; asc  ;;
mysql tables in use 1, locked 1
MySQL thread id 10520696, OS thread handle 139667256985344, query id 301142683 ***.190 exam updating
 26: len 4; hex 5df58817; asc ]   ;;
 3: len 6; hex e69cb1e888aa; asc       ;;
 13: len 0; hex ; asc ;;
 10: len 18; hex 343430333034323030383032303230343334; asc 440304200802020434;;
 12: len 4; hex 00000000; asc     ;;
 17: len 1; hex 01; asc  ;;
 15: len 10; hex 323030382d31302d3033; asc 2008-10-03;;
 19: len 4; hex 00000013; asc     ;;
 20: len 4; hex 00000000; asc     ;;
 7: len 30; hex 243279243130247756783376524c2e38756457306945644f6e5061734f53; asc $2y$10$wVx3vRL.8udW0iEdOnPasOS; (total 60 bytes);
 9: len 30; hex 5b2268747470733a5c2f5c2f6578616d2d313235333338363431342e6669; asc ["https:\/\/exam-1253386414.fi; (total 205 bytes);
28 lock struct(s), heap size 3520, 28 row lock(s), undo log entries 1850
 26: len 4; hex 5df58817; asc ]   ;;
 23: len 4; hex 5df5863f; asc ]  ?;;
 17: len 1; hex 02; asc  ;;
 26: len 4; hex 5df5863f; asc ]  ?;;
RECORD LOCKS space id 301 page no 28 n bits 88 index PRIMARY of table `exam`.`examinees` trx id 4006767 lock_mode X locks rec but not gap
 0: len 4; hex 00000374; asc    t;;
 4: len 9; hex e69e97e7bfa0e78fa0; asc          ;;
 15: len 10; hex 323030382d30322d3032; asc 2008-02-02;;
TRANSACTION 4005686, ACTIVE 1709 sec starting index read
 2: len 7; hex 29000001cf11da; asc )      ;;
 8: len 1; hex 01; asc  ;;
 4: len 9; hex e69e97e7bfa0e78fa0; asc          ;;
 5: len 15; hex 38353836343036304071712e636f6d; asc 85864060@qq.com;;
 9: len 30; hex 5b2268747470733a5c2f5c2f6578616d2d313235333338363431342e6669; asc ["https:\/\/exam-1253386414.fi; (total 205 bytes);
 18: len 24; hex e883a1e88081e5b888e280ad203135333237323433333934; asc              15327243394;;
 6: len 11; hex 3138313239393331303638; asc 18129931068;;
 14: len 30; hex 68747470733a2f2f6578616d2d313235333338363431342e66696c652e6d; asc https://exam-1253386414.file.m; (total 92 bytes);
update `examinees` set `token` = 'eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJpc3MiOiJodHRwOlwvXC9leGFtLmNvZGVwa3UuY29tXC9hcGlcL2V4YW1pbmVlXC9sb2dpbiIsImlhdCI6MTU3NjM3MzQ1NCwiZXhwIjoxNjEyMzczNDU0LCJuYmYiOjE1NzYzNzM0NTQsImp0aSI6IlhXWmZNSUdNTjVLSTd6U0kiLCJzdWIiOjE2MjYsInBydiI6IjQ2NzBiY2JjOGM1OTUyY2U3ZjdhMWY0ODk5Yjk1NGM1NWI1NjQzMmQifQ.zUGTJnfnGREKzbkASKjVtPVaac_3bMXXUVuDs7vdDKE', `login_count` = 4, `last_login_at` = '2019-12-15 09:30:54', `examinees`.`updated_at` = '2019-12-15 09:30:54' where `id` = 1626
 1: len 6; hex 0000003d236f; asc    =#o;;
 2: len 7; hex 29000001cf11da; asc )      ;;
 25: len 4; hex 5d68cbfc; asc ]h  ;;
 6: len 11; hex 3138313239393331303638; asc 18129931068;;
 15: len 10; hex 323030382d31302d3033; asc 2008-10-03;;
 23: len 4; hex 5df58817; asc ]   ;;
 0: len 4; hex 0000065a; asc    Z;;
 11: len 1; hex 81; asc  ;;
 12: len 4; hex 00000000; asc     ;;
 15: len 10; hex 323030382d31302d3033; asc 2008-10-03;;
 23: len 4; hex 5df58817; asc ]   ;;
 0: len 4; hex 0000065a; asc    Z;;
 9: len 30; hex 5b2268747470733a5c2f5c2f736372617463682d776f726b732d31323533; asc ["https:\/\/scratch-works-1253; (total 215 bytes);
 21: len 30; hex 65794a30655841694f694a4b563151694c434a68624763694f694a49557a; asc eyJ0eXAiOiJKV1QiLCJhbGciOiJIUz; (total 337 bytes);
 16: len 1; hex 81; asc  ;;
 21: len 30; hex 65794a30655841694f694a4b563151694c434a68624763694f694a49557a; asc eyJ0eXAiOiJKV1QiLCJhbGciOiJIUz; (total 339 bytes);
 17: len 1; hex 01; asc  ;;
 4: len 6; hex e983ade99c9e; asc       ;;
 5: len 15; hex 31323038383438374071712e636f6d; asc 12088487@qq.com;;
 19: len 4; hex 00000013; asc     ;;
 24: SQL NULL;
 2: len 7; hex 38000001a3284a; asc 8    (J;;
 20: len 4; hex 00000000; asc     ;;
 25: len 4; hex 5dea312c; asc ] 1,;;