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 (
    33725, 43652, 47613, 3288, 28159, 6372, 
    33723, 3287, 3286, 3872, 1278, 855, 
    854, 35165, 35176, 35173, 35170, 35172, 
    6092, 35731, 23261, 46982, 464, 3021, 
    35168, 41429, 6093, 33724, 856, 460, 
    34053, 455
  )

Query time 0.01399

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": 33,
          "filtered": 100,
          "index_condition": "p.product_id in (33725,43652,47613,3288,28159,6372,33723,3287,3286,3872,1278,855,854,35165,35176,35173,35170,35172,6092,35731,23261,46982,464,3021,35168,41429,6093,33724,856,460,34053,455)"
        }
      },
      {
        "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
        }
      }
    ]
  }
}