SELECT 
  f.feature_id, 
  f.purpose, 
  p.product_id, 
  p.parent_product_id, 
  g.id, 
  g.code 
FROM 
  cscart_product_variation_group_features AS f 
  INNER JOIN cscart_product_variation_groups AS g ON f.group_id = g.id 
  INNER JOIN cscart_product_variation_group_products AS p ON f.group_id = p.group_id 
WHERE 
  p.product_id IN (
    9551, 12820, 10896, 8305, 10313, 9789, 
    8328, 12819, 7680, 10017, 6903, 9492, 
    9786, 8332, 8352, 8358, 6902, 9837, 
    9792, 10452, 8121, 9788, 6901, 12826, 
    12825
  )

Query time 0.00042

JSON explain

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