SELECT 
  f.feature_id, 
  f.purpose, 
  p.product_id, 
  p.parent_product_id, 
  g.id, 
  g.code 
FROM 
  tmall_product_variation_group_features AS f 
  INNER JOIN tmall_product_variation_groups AS g ON f.group_id = g.id 
  INNER JOIN tmall_product_variation_group_products AS p ON f.group_id = p.group_id 
WHERE 
  p.product_id IN (
    94, 96, 114, 108, 121, 103, 95, 112, 89, 
    116, 82, 85, 88, 110, 93, 87, 118, 83, 
    123, 119
  )

Query time 0.00923

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost": 0.02190873,
    "nested_loop": [
      {
        "table": {
          "table_name": "g",
          "access_type": "system",
          "possible_keys": ["PRIMARY"],
          "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": ["const"],
          "loops": 1,
          "rows": 2,
          "cost": 0.00325828,
          "filtered": 100
        }
      },
      {
        "table": {
          "table_name": "p",
          "access_type": "ref",
          "possible_keys": ["PRIMARY", "idx_group_id"],
          "key": "idx_group_id",
          "key_length": "3",
          "used_key_parts": ["group_id"],
          "ref": ["const"],
          "loops": 2,
          "rows": 7,
          "cost": 0.01865045,
          "filtered": 100,
          "attached_condition": "p.product_id in (94,96,114,108,121,103,95,112,89,116,82,85,88,110,93,87,118,83,123,119)"
        }
      }
    ]
  }
}