Error : Lock wait timeout exceeded; try restarting transaction (no replies)

Hello,
My application try to update one column with this mysql statement:

UPDATE e_user
SET credit = credit - 0.009000
WHERE username = 'abc' AND credit >= 0.009000

Sometimes after the update i get this error:

Lock wait timeout exceeded; try restarting transaction

After searching about this issue i try to set this parameter to mysql cluster

TransactionDeadlockDetectionTimeout=10000
HeartbeatIntervalDbDb=3000
HeartbeatIntervalDbApi=3000

and the error is the same.

What can i do for this?