MySQl database slow queries

Hello

I notice in MySQL server log there are slow queries, like

SELECT tickets.ticketid FROM swtickets AS tickets
LEFT JOIN swticketlocks AS ticketlocks ON (tickets.ticketid = ticketlocks.ticketid)
LEFT JOIN swticketwatchers AS ticketwatchers ON (tickets.ticketid = ticketwatchers.ticketid AND ticketwatchers.staffid = '895')
LEFT JOIN swusers AS users ON (tickets.userid = users.userid)
LEFT JOIN swusergroups AS usergroups ON (users.usergroupid =...

MySQl database slow queries