Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8da1c4fd1014233b5daada6f4f573c9c9b5bc9b7399c7170b0e4c2bb5cf00b61' 
  AND token = 'L7edREgn/QWAqapURZ7WEv67Tmkw2a8dBVlgUr+Aj/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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