Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '473e94a2dff94f7d3b1ce789ab11844e8a53bde2da2c6bfb2463b5484457c549' 
  AND token = 'bxRiJGQfew7mjJIWqjOYb8DxQ+hSw1ojU6933BAbYaw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00009

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}