SELECT 
  COUNT(
    DISTINCT(cscart_pages.page_id)
  ) 
FROM 
  cscart_pages 
  LEFT JOIN cscart_page_descriptions ON cscart_pages.page_id = cscart_page_descriptions.page_id 
  AND cscart_page_descriptions.lang_code = 'tr' 
  LEFT JOIN cscart_seo_names ON cscart_seo_names.object_id = cscart_pages.page_id 
  AND cscart_seo_names.type = 'a' 
  AND cscart_seo_names.dispatch = '' 
  AND cscart_seo_names.lang_code = 'tr' 
WHERE 
  1 
  AND cscart_pages.parent_id IN (8) 
  AND cscart_pages.status IN ('A') 
  AND cscart_pages.company_id IN (0, 3, 4) 
  AND cscart_pages.page_type IN ('B') 
  AND (
    cscart_pages.usergroup_ids = '' 
    OR FIND_IN_SET(0, cscart_pages.usergroup_ids) 
    OR FIND_IN_SET(1, cscart_pages.usergroup_ids)
  ) 
  AND (
    cscart_pages.use_avail_period = 'N' 
    OR (
      cscart_pages.use_avail_period = 'Y' 
      AND cscart_pages.avail_from_timestamp <= 1741892807 
      AND (
        cscart_pages.avail_till_timestamp >= 1741892807 
        OR cscart_pages.avail_till_timestamp = 0
      )
    )
  ) 
ORDER BY 
  cscart_pages.timestamp desc

Query time 0.00040

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE cscart_pages ref parent_id parent_id 3 const 1 Using where
1 SIMPLE cscart_seo_names ref PRIMARY,dispatch PRIMARY 206 hobilifedt.cscart_pages.page_id,const,const,const 1 Using where; Using index

Result

COUNT(DISTINCT(cscart_pages.page_id))
0