Sandbox

SELECT 
  cscart_tags.tag_id, 
  cscart_tag_links.object_id, 
  cscart_tag_links.object_type, 
  cscart_tags.tag, 
  cscart_tags.status, 
  COUNT(cscart_tag_links.tag_id) as popularity 
FROM 
  cscart_tags 
  LEFT JOIN cscart_tag_links ON cscart_tag_links.tag_id = cscart_tags.tag_id 
WHERE 
  1 
  AND cscart_tag_links.object_type = 'P' 
  AND cscart_tags.status IN ('A') 
  AND cscart_tag_links.object_id = 816 
GROUP BY 
  cscart_tags.tag_id 
ORDER BY 
  cscart_tags.tag asc

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}