MyBB SQL Error

MyBB has experienced an internal SQL error and cannot continue.

SQL Error:
1062 - Duplicate entry '1516346831-54.226.41.91-0' for key 'datetime'
Query:
UPDATE mybb_lastvisitors SET `ip`='54.226.41.91', `uid`='0', `username`='', `datetime`='1516346831', `referrer`='', `url`='/showthread.php?tid=76320&pid=107887', `info`='CCBot/2.0 (http://commoncrawl.org/faq/)' WHERE ip='54.36.148.29' AND datetime='1516346625'