SELECT actor_name,

       DATE_FORMAT(MAX(log_timestamp), '%Y-%m-%d %H:%i:%s') AS 'last action'

FROM actor

LEFT JOIN user_groups ON ug_user = actor_user

LEFT JOIN logging_userindex ON log_actor = actor_id AND log_type IN ('delete', 'protect', 'block')

WHERE ug_group = 'sysop'

GROUP BY actor_name

HAVING (MAX(log_timestamp) < '20160602'

        OR MAX(log_timestamp) IS NULL)

ORDER BY MAX(log_timestamp) ASC;