SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = '8f24a92b85ab41f20da975819c28898bcb9349da7f7276262601e33d504f3343' 
  AND token = 'iQiwd9Dv2rpgB9fKsDvjWiyXbisOk82/CNvHMepOllA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00783

JSON explain

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