$('#main_chekout').not($('#main_chekout [hidden],#main_chekout [hidden] *')).serialize()
- не помогло $form=$('#main_chekout');
$hidden_inputs=$form.find('[hidden] input,[hidden]');
$hidden_inputs.attr("disabled", true);
console.log($form.serialize());
$hidden_inputs.removeAttr("disabled");