SQL info: MySQL Query Error

Time: 2019-10-22 7:35am
Script: /keshi.php

SQL: INSERT INTO t_session (sid,uid,islogin,isadmin, updated, sessiondata ) VALUES ('540d71','','','', '1571700901', 'a:0:{}')
Error: Duplicate entry '540d71' for key 'PRIMARY'
Errno.: 1062