how to go back to login page if given wrong php GET credentials?

so im given 3 variables on my login page from an outside source, if one of those do not belong in the database I want it to just go to the normal login.php page. as of right now it stays on that page and does not change the url even though the vars are not in the db. i give it localhost/john/login.php?uniqueID=BmWDLlkcyU&compID=2&tempID=22 , but tempID 22 does not exist so i want it to revert to login.php

     $uniqueID = $_GET['uniqueID'];
     $compid =  $_GET['compID'];
     $tempID = $_GET['tempID'];

     $checkUnique = mysqli_query($conn, "SELECT unique_id from answers WHERE unique_id = '$uniqueID' and template_id = '$tempID'");
     $checkComp = mysqli_query($conn, "SELECT company_id from t_list WHERE company_id = '$compid'");


 if(!$checkUnique)
{

   header("Location: login.php"); 
  exit;
 }
else if(!$checkComp)
  {
    header("Location: login.php"); 
   exit;
   }