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 (
    7704, 7703, 1202, 2738, 7304, 7307, 7303, 
    7305, 7306, 7766, 4606, 2739, 4122, 
    7302, 2740, 2741, 2742, 2743, 7769, 
    7770, 2744, 3544, 3545, 3543
  )

Query time 0.00026

JSON explain

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