Количество активных и доступных элементов в разделах инфоблока

...
$strSelect = $sSelect.",COUNT(DISTINCT BE.ID) as ELEMENT_CNT".(isset($obUserFieldsSql)? $obUserFieldsSql->GetSelect(): "");
...
LEFT JOIN b_iblock_element BE 
ON (BSE.IBLOCK_ELEMENT_ID=BE.ID AND ((BE.WF_STATUS_ID=1 AND BE.WF_PARENT_ELEMENT_ID IS NULL ) AND BE.IBLOCK_ID = BS.IBLOCK_ID

array(3) {
  ["ID"]=>
  string(3) "702"
  ["SORT"]=>
  string(3) "100"
  ["ELEMENT_CNT"]=>
  string(4) "6840"
}
array(3) {
  ["ID"]=>
  string(3) "835"
  ["SORT"]=>
  string(4) "2440"
  ["ELEMENT_CNT"]=>
  string(4) "5396"
}
float(0.022021)

array(2) {
  [0]=>
  array(2) {
    ["CNT"]=>
    string(4) "1279"
    ["IBLOCK_SECTION_ID"]=>
    string(3) "702"
  }
  [1]=>
  array(2) {
    ["CNT"]=>
    string(3) "271"
    ["IBLOCK_SECTION_ID"]=>
    string(3) "835"
  }
}
float(0.01721)

\Bitrix\Main\Loader::includeModule('iblock');
\Bitrix\Main\Loader::includeModule('catalog');
$s1 = microtime();
$res = \CIBlockSection::GetList(array("SORT"=>"ASC"), array('ID' => array(702,835)), true, array('ID'));
while($sc = $res->Fetch())
{
   var_dump($sc);
}
var_dump(microtime()-$s1);

$s2 = microtime();
$res = \Bitrix\Iblock\SectionElementTable::getList(array(
   'select' => array('CNT', 'IBLOCK_SECTION_ID'),
   'filter' => array(
      'IBLOCK_SECTION_ID' => array(702,835),
      'PRODUCT.AVAILABLE' => 'Y',
      'ELEMENT.ACTIVE' => 'Y'
   ),
   'runtime' => array(
      new \Bitrix\Main\Entity\ExpressionField('CNT', 'COUNT(*)'),
      'PRODUCT' => array(
         'data_type' => '\Bitrix\Catalog\ProductTable',
         'reference' => array(
            '=this.IBLOCK_ELEMENT_ID' => 'ref.ID'
         ),
         'join_type' => 'left'
      ),
      'ELEMENT' => array(
         'data_type' => '\Bitrix\Iblock\ElementTable',
         'reference' => array(
            '=this.IBLOCK_ELEMENT_ID' => 'ref.ID'
         ),
         'join_type' => 'left'
      )
   )
));
var_dump($res->fetchAll());
var_dump(microtime()-$s2);