Operational error 'Deadlock found' from SQLAlchemy with mysql when trying in-flight lock under load about peekabooav HOT 4 CLOSED

2020-07-22 10:57:10,727 - peekaboo.server - (Request-23) - DEBUG - New connection incoming.
2020-07-22 10:57:10,761 - peekaboo.server - (Request-23) - INFO - Got run_analysis request for /home/michael/PeekabooAV/foo.py
2020-07-22 10:57:10,761 - peekaboo.sample - (Request-23) - DEBUG - meta_info_request = scan-file
2020-07-22 10:57:10,761 - peekaboo.sample - (Request-23) - DEBUG - meta_info_full_name = /home/michael/PeekabooAV/foo.py
2020-07-22 10:57:10,764 - sqlalchemy.engine.base.Engine - (Request-23) - INFO - BEGIN (implicit)
2020-07-22 10:57:10,792 - sqlalchemy.engine.base.Engine - (Request-23) - INFO - INSERT INTO in_flight_samples_v7 (sha256sum, instance_id, start_tim
e) VALUES (%s, %s, %s)
2020-07-22 10:57:10,794 - sqlalchemy.engine.base.Engine - (Request-23) - INFO - ('fedb5b37f2f7d921c58119c82be428d134c34ba606727002d44bbb0d1ddfbc05'
, 10, datetime.datetime(2020, 7, 22, 10, 57, 10, 763630))
2020-07-22 10:57:10,820 - sqlalchemy.engine.base.Engine - (Request-23) - INFO - ROLLBACK
2020-07-22 10:57:10,822 - peekaboo.queuing - (Request-23) - ERROR - Unable to mark sample as in flight: (MySQLdb._exceptions.OperationalError) (121
3, 'Deadlock found when trying to get lock; try restarting transaction')
[SQL: INSERT INTO in_flight_samples_v7 (sha256sum, instance_id, start_time) VALUES (%s, %s, %s)]
[parameters: ('fedb5b37f2f7d921c58119c82be428d134c34ba606727002d44bbb0d1ddfbc05', 10, datetime.datetime(2020, 7, 22, 10, 57, 10, 763630))]
(Background on this error at: http://sqlalche.me/e/e3q8

MariaDB [peekaboo]> SHOW ENGINE INNODB STATUS;
------------------------
LATEST DETECTED DEADLOCK
------------------------
2020-07-22 10:57:10 7fb758b04700
*** (1) TRANSACTION:
TRANSACTION 15432303, ACTIVE 0 sec inserting
mysql tables in use 1, locked 1
LOCK WAIT 3 lock struct(s), heap size 1184, 2 row lock(s)
MySQL thread id 235, OS thread handle 0x7fb758942700, query id 4776 localhost peekaboo update
INSERT INTO in_flight_samples_v7 (sha256sum, instance_id, start_time) VALUES ('fedb5b37f2f7d921c58119c82be428d134c34ba606727002d44bbb0d1ddfbc05', 8
, '2020-07-22 10:57:10.764760')
*** (1) WAITING FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 593 page no 3 n bits 72 index `PRIMARY` of table `peekaboo`.`in_flight_samples_v7` trx table locks 1 total table locks 2  trx
 id 15432303 lock_mode X locks rec but not gap waiting lock hold time 0 wait time before grant 0
*** (2) TRANSACTION:
TRANSACTION 15432304, ACTIVE 0 sec inserting
mysql tables in use 1, locked 1
3 lock struct(s), heap size 1184, 2 row lock(s)
MySQL thread id 229, OS thread handle 0x7fb758b04700, query id 4777 localhost peekaboo update
INSERT INTO in_flight_samples_v7 (sha256sum, instance_id, start_time) VALUES ('fedb5b37f2f7d921c58119c82be428d134c34ba606727002d44bbb0d1ddfbc05', 1
0, '2020-07-22 10:57:10.763630')
*** (2) HOLDS THE LOCK(S):
RECORD LOCKS space id 593 page no 3 n bits 72 index `PRIMARY` of table `peekaboo`.`in_flight_samples_v7` trx table locks 1 total table locks 2  trx
 id 15432304 lock mode S locks rec but not gap lock hold time 0 wait time before grant 0
*** (2) WAITING FOR THIS LOCK TO BE GRANTED:
RECORD LOCKS space id 593 page no 3 n bits 72 index `PRIMARY` of table `peekaboo`.`in_flight_samples_v7` trx table locks 1 total table locks 2  trx
 id 15432304 lock_mode X locks rec but not gap waiting lock hold time 0 wait time before grant 0
*** WE ROLL BACK TRANSACTION (2)