bir denermisiniz:
<?php
require __DIR__ . '/config.php';
$simdiki_zaman = time();
$repacks = $spexcon->query("SELECT * FROM repacks WHERE btarih >= ".$simdiki_zaman." AND st = '0'");
                           
foreach ($repacks as $repack) {
    $spexcon->query("UPDATE repacks SET st='1' WHERE id=".$repack["id"]);
}
?>