SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = '5f439a4be56d6982ea39e5048cc7b9b28249d466dc5b2afcd49f9ac38d308754' 
  AND token = 'dsc+TJchMBjUgUatR5+zx1eKzu1rQ9OcZQPOylwnaho=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00756

JSON explain

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