Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5c8b92a6f3505688ef8eb212f46688d59dda25664f35a46e3fd071bb5d3624a' 
  AND token = '84VXlk4kCs9Wrg7ZN9V0pdGTXGpLC1eHQxp1q+iyV8I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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