[Solved] Delete row if key code is there for more than 15 min

Another way would be this:

PHP Code:

$dt = new Datetime();   //create object for current date/time
$dt->modify('15 minutes ago');   //substract 15 minutes
$sdt = $dt->format('Y-m-d H:i:s');  //format it into a datetime string

$this->db->where('date_modified <' , $sdt);