SELECT 
  1 
FROM 
  tmall_lock_keys 
WHERE 
  key_id = '5de6d0ccc0a38b5b6688011d5dd34ace2f62efccd02fe843e416ed8cfc6e6b5f' 
  AND token = 'yBC6cxd75HWnn4WwUFU86p8nZDdd+cULCvAmXFt2w1o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00811

JSON explain

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