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 (
    3569, 31636, 41293, 31637, 41339, 31635, 
    3876, 1975, 48980, 37850, 43824, 3577, 
    2305, 3862, 1942, 6368, 3519, 3863, 
    35730, 3578, 3864, 3861, 35731, 37774, 
    49192, 464, 632, 37315, 47163, 1323, 
    3579, 47162
  )

Query time 0.00204

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 (3569,31636,41293,31637,41339,31635,3876,1975,48980,37850,43824,3577,2305,3862,1942,6368,3519,3863,35730,3578,3864,3861,35731,37774,49192,464,632,37315,47163,1323,3579,47162)"
        }
      },
      {
        "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
        }
      }
    ]
  }
}