MyBB SQL Error

MyBB has experienced an internal SQL error and cannot continue.

SQL Error:
1062 - Duplicate entry '1516708324-54.234.190.237-0' for key 'datetime'
Query:
UPDATE mybb_lastvisitors SET `ip`='54.234.190.237', `uid`='0', `username`='', `datetime`='1516708324', `referrer`='', `url`='/showthread.php?tid=76320&pid=153185', `info`='CCBot/2.0 (http://commoncrawl.org/faq/)' WHERE ip='204.12.226.26' AND datetime='1516708080'