Sandbox

SELECT 
  p.product_id, 
  ifnull(
    count(dp.post_id), 
    0
  ) as discussion_amount_posts 
FROM 
  cscart_discussion 
  INNER JOIN cscart_products as p ON (
    cscart_discussion.object_id = p.product_id
  ) 
  INNER JOIN cscart_discussion_posts as dp ON (
    cscart_discussion.thread_id = dp.thread_id 
    AND cscart_discussion.object_type = 'P' 
    AND cscart_discussion.company_id = 1
  ) 
WHERE 
  dp.status = 'A' 
  and p.product_id in (
    21, 
    31, 
    46, 
    47, 
    48, 
    49, 
    50, 
    51, 
    53, 
    88, 
    91, 
    92, 
    105, 
    126, 
    129, 
    137, 
    138, 
    139, 
    21567, 
    22712, 
    22713, 
    22714, 
    22715, 
    22716, 
    50989, 
    51081, 
    51082, 
    51083, 
    51085, 
    51086, 
    51087, 
    51088, 
    51089, 
    51090, 
    51091, 
    51092, 
    51093, 
    51095, 
    51096, 
    51097, 
    51098, 
    51099, 
    51100, 
    51101, 
    51102, 
    51103, 
    51105, 
    51121, 
    51122, 
    51123, 
    51125, 
    51126, 
    51127, 
    51128, 
    51129, 
    51152, 
    51153, 
    51154, 
    51155, 
    51156, 
    51157, 
    51158, 
    51159, 
    51160, 
    51172, 
    51173, 
    51174, 
    51176, 
    51221, 
    51223, 
    51224, 
    51296, 
    51297, 
    51298, 
    51299, 
    51300, 
    51301, 
    51302, 
    51303, 
    51304, 
    51305, 
    51306, 
    51307, 
    51308, 
    51309, 
    51316, 
    51317, 
    51318, 
    51319, 
    51320, 
    51321, 
    51322, 
    51323, 
    51324, 
    51340, 
    51341, 
    51342, 
    51343, 
    51366, 
    51367, 
    51368, 
    51369, 
    51370, 
    51371, 
    51372, 
    51373, 
    51395, 
    51396, 
    51397, 
    51443, 
    51452, 
    51453, 
    51496, 
    51497, 
    51498, 
    51555, 
    51556, 
    51564, 
    51565, 
    51566, 
    51567, 
    51568, 
    51569, 
    51570, 
    51571, 
    51572, 
    51573, 
    51574, 
    51575, 
    51576, 
    51577, 
    51578, 
    51579, 
    51580, 
    51581, 
    51582, 
    51583, 
    51584, 
    51585, 
    51586
  ) 
GROUP BY 
  p.product_id

Query time 0.00074

JSON explain

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