SELECT * FROM session WHERE
EXTRACT(EPOCH FROM lastop) < EXTRACT(EPOCH FROM CURRENT_TIMESTAMP) - $timeout

##</code><code>##

SELECT * FROM session WHERE
UNIX_TIMESTAMP(lastop) < UNIX_TIMESTAMP(CURRENT_TIMESTAMP) - $timeout

##</code><code>##

SELECT * FROM session WHERE
lastop < now() - interval $timeout second

##</code><code>##

SELECT * FROM session WHERE
lastop < now() - interval '$timeout second'