SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd124382f2b8fe207caf592bb9520759bc5200091e479ffed64510aa04388fc18' 
  AND token = '47cctvWmzAQhWy/Roty4pm3czK+N6sNGBSyhL3dVCW4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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