code: public function findElementToAutoUnpublish($siteId, StatusInterface $publishedStatus)
      {
          $date = new \Mongodate(strtotime(date('d F Y')));
          $statusId = new \MongoId($publishedStatus->getId());
  
          $qa = $this->createAggregationQuery();
  
          $filter = array(
              'siteId' => $siteId,
              'deleted' => false,
              'status._id' => $statusId,
              'status.outOfWorkflow' => false,
              'unpublishDate' => array('$lte' => $date)
          );
  
          $qa->match($filter);
          $qa->sort(array('createdAt' => 1));
  
          return $this->hydrateAggregateQuery($qa);
      }
docs: Find all elements (in all versions and all langauges) ready to be auto-unpublished
  
  @param string          $siteId
  @param StatusInterface $publishedStatus
  
  @return array