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 (
    2686, 2568, 15042, 14456, 2188, 13664, 
    12195, 14044, 15057, 12955, 2645, 2646, 
    2333, 2331, 2330, 2792, 2793, 11131, 
    2794, 11132, 2798, 2795, 2797, 11890
  )

Query time 0.00024

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": 24,
      "filtered": 100,
      "index_condition": "p.product_id in (2686,2568,15042,14456,2188,13664,12195,14044,15057,12955,2645,2646,2333,2331,2330,2792,2793,11131,2794,11132,2798,2795,2797,11890)"
    },
    "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
    }
  }
}