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 (
    5578, 5472, 5457, 5588, 5462, 5579, 5590, 
    5478, 5580, 31887, 31891, 5960, 5957, 
    5961, 31894, 16802, 35733, 5448, 31893, 
    4363, 5956, 31895, 4361, 5451, 5479, 
    4366, 4360, 5591, 5485, 5587, 31889, 
    5963
  )

Query time 0.00263

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "table": {
          "table_name": "p",
          "access_type": "range",
          "possible_keys": ["PRIMARY", "idx_group_id"],
          "key": "PRIMARY",
          "key_length": "3",
          "used_key_parts": ["product_id"],
          "rows": 32,
          "filtered": 100,
          "index_condition": "p.product_id in (5578,5472,5457,5588,5462,5579,5590,5478,5580,31887,31891,5960,5957,5961,31894,16802,35733,5448,31893,4363,5956,31895,4361,5451,5479,4366,4360,5591,5485,5587,31889,5963)"
        }
      },
      {
        "table": {
          "table_name": "f",
          "access_type": "ref",
          "possible_keys": ["idx_group_id"],
          "key": "idx_group_id",
          "key_length": "3",
          "used_key_parts": ["group_id"],
          "ref": ["dev_db.p.group_id"],
          "rows": 1,
          "filtered": 100
        }
      },
      {
        "table": {
          "table_name": "g",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "3",
          "used_key_parts": ["id"],
          "ref": ["dev_db.p.group_id"],
          "rows": 1,
          "filtered": 100
        }
      }
    ]
  }
}