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 (
    2527, 11680, 2515, 2516, 2517, 2518, 
    15082, 2457, 2458, 2459, 2460, 2461, 
    2523, 2519, 2521, 2522
  )

Query time 0.00021

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": 16,
      "filtered": 100,
      "index_condition": "p.product_id in (2527,11680,2515,2516,2517,2518,15082,2457,2458,2459,2460,2461,2523,2519,2521,2522)"
    },
    "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
    }
  }
}