phpMyAdmin trigger error
Instead of editing the existing trigger, try to open a new SQL Console and try this :

DROP TRIGGER IF EXISTS `AuditSetExpiryTokens`;
DELIMITER $$
CREATE DEFINER = CURRENT_USER TRIGGER `AuditSetExpiryTokens` BEFORE 
INSERT ON `token` FOR EACH ROW
BEGIN
 SET NEW.expiry=DATE_ADD(NOW(),INTERVAL NEW.duration SECOND);
 SET NEW.delete_date=DATE_ADD(NOW(),INTERVAL(NEW.duration+(3600*2)) SECOND);
END$$
DELIMITER ;