Exception Caught

SQLSTATE[40001]: Serialization failure: 1213 Deadlock found when trying to get lock; try restarting transaction:
DELETE `exp_cartthrob_cart` FROM `exp_cartthrob_cart` LEFT OUTER JOIN `exp_cartthrob_sessions` ON `exp_cartthrob_cart`.`id` = `exp_cartthrob_sessions`.`cart_id` WHERE `exp_cartthrob_sessions`.`cart_id` IS NULL

mysqli_connection.php:116