SELECT 
  * 
FROM 
  tmall_product_feature_variants 
WHERE 
  variant_id IN (89, 46, 63, 61, 59, 64, 60, 62)

Query time 0.00987

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost": 0.01458715,
    "nested_loop": [
      {
        "table": {
          "table_name": "tmall_product_feature_variants",
          "access_type": "range",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "3",
          "used_key_parts": ["variant_id"],
          "loops": 1,
          "rows": 8,
          "cost": 0.01458715,
          "filtered": 100,
          "index_condition": "tmall_product_feature_variants.variant_id in (89,46,63,61,59,64,60,62)"
        }
      }
    ]
  }
}