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 (
    92, 
    370, 
    374, 
    376, 
    382, 
    510, 
    1610, 
    1612, 
    1613, 
    1614, 
    1615, 
    1616, 
    1617, 
    1618, 
    1626, 
    5476, 
    5473, 
    1843, 
    1841, 
    1840, 
    486, 
    3844, 
    1842, 
    3854, 
    3853, 
    3852, 
    3851, 
    3850, 
    3849, 
    3848, 
    3847, 
    3846, 
    3845, 
    3843, 
    3856, 
    3785, 
    3841, 
    3840, 
    3839, 
    3838, 
    3837, 
    3836, 
    3835, 
    3834, 
    3833, 
    3832, 
    3855, 
    3857, 
    3830, 
    3801, 
    3882, 
    3881, 
    3880, 
    3806, 
    3805, 
    3877, 
    3808, 
    3807, 
    3874, 
    3873, 
    3812, 
    3870, 
    3815, 
    3814, 
    3813, 
    3867, 
    3866, 
    3865, 
    3864, 
    3863, 
    3862, 
    3861, 
    3824, 
    3859, 
    3831, 
    3829, 
    3773, 
    3786, 
    3797, 
    3796, 
    3795, 
    3794, 
    3793, 
    3792, 
    3791, 
    3790, 
    3789, 
    3788, 
    3787, 
    3842, 
    3799, 
    3782, 
    3781, 
    3780, 
    3779, 
    3778, 
    3777, 
    3776, 
    3775, 
    3774, 
    3798, 
    3800, 
    3828, 
    3860, 
    3827, 
    3858, 
    3823, 
    3822, 
    3821, 
    3820, 
    3819, 
    3818, 
    3817, 
    3816, 
    3869, 
    3868, 
    3872, 
    3871, 
    3811, 
    3810, 
    3809, 
    3876, 
    3875, 
    3879, 
    3878, 
    3804, 
    3803, 
    3802, 
    3883, 
    3884
  ) 
GROUP BY 
  p.product_id

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}