SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d24923bdbf241b218c792b992243fe93580eca9c4189e291a3b5254c892464f' 
  AND token = 'bYJSPtdlJVrghDPItidoM2UL8qTjN15IGf6i54JwTdM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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