And if you want it to *SAY* "active" or "expired", that's trivial as well:
SELECT IF( updated > DATE_SUB( CURDATE(), INTERVAL 5 DAY ) , 'active', 'expired' ) AS postingStatus,
... other fields...
memberid = $currentMemberId
OR updated > DATE_SUB( CURDATE(), INTERVAL 5 DAY )
Though you could just as easily do the "IF" test in PHP code if you preferred.