SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = '0e8f2d3be818573ec194419e6e320f59add51adcd38e7a80caf3d6994c1f81e5' 
  AND token = '2kPQDWJcm8Oq55zjf9YlHdWGTqP3qPp4c24kjtB7cec=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00892

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}