MyBB SQL Error

MyBB has experienced an internal SQL error and cannot continue.

SQL Error:
1062 - Duplicate entry '1518977527-54.227.17.101-0' for key 'datetime'
Query:
UPDATE mybb_lastvisitors SET `ip`='54.227.17.101', `uid`='0', `username`='', `datetime`='1518977527', `referrer`='', `url`='/showthread.php?tid=85446&pid=157412', `info`='CCBot/2.0 (http://commoncrawl.org/faq/)' WHERE ip='54.227.17.101' AND datetime='1518977348'