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 (
    12731, 12725, 12727, 12724, 10923, 10920, 
    10922, 12730, 10918, 10916, 10919, 
    10833, 10837, 10835, 10836, 10834, 
    10819, 10827, 10829, 10830, 10832, 
    10828, 12726, 12732, 12598, 12599, 
    12601, 12603, 12600, 12602
  )

Query time 0.00022

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 (12731,12725,12727,12724,10923,10920,10922,12730,10918,10916,10919,10833,10837,10835,10836,10834,10819,10827,10829,10830,10832,10828,12726,12732,12598,12599,12601,12603,12600,12602)"
    },
    "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
    }
  }
}