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 (
    4970, 4963, 4974, 4978, 4956, 4962, 4959, 
    12457, 11777, 12268, 12270, 12271, 
    12272, 12275, 12276, 12255, 12257, 
    12258, 12259, 12260, 12261, 12262, 
    12269, 12263, 12264, 12265, 12266, 
    12267, 12273, 12274
  )

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "p",
      "access_type": "range",
      "possible_keys": ["PRIMARY", "idx_group_id"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "rows": 30,
      "filtered": 100,
      "index_condition": "p.product_id in (4970,4963,4974,4978,4956,4962,4959,12457,11777,12268,12270,12271,12272,12275,12276,12255,12257,12258,12259,12260,12261,12262,12269,12263,12264,12265,12266,12267,12273,12274)"
    },
    "table": {
      "table_name": "g",
      "access_type": "eq_ref",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["id"],
      "ref": ["ymonline_livedata.p.group_id"],
      "rows": 1,
      "filtered": 100
    },
    "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": ["ymonline_livedata.p.group_id"],
      "rows": 1,
      "filtered": 100
    }
  }
}