DELETE t1
FROM best_times t1
INNER JOIN (
    SELECT MIN(id) as min_id, map_uid, player_login, best_time
    FROM best_times
    GROUP BY map_uid, player_login, best_time
) t2
ON t1.map_uid = t2.map_uid
AND t1.player_login = t2.player_login
AND t1.best_time = t2.best_time
AND t1.id > t2.min_id;