How do you retrieve info for each resume? Is there some "resumeID" value you pass via the URL or something? If so, you could do something like:
$query = "SELECT IF(time_upload < NOW() - INTERVAL 90 DAY, NULL, filename) FROM foo WHERE id=$id";
$exec = mysql_query($query);
$file = mysql_result($exec, 0);
if($file === NULL) {
// resume must be older than 90 days, or one was never uploaded
} else {
// $file contains the "filename" column value
}