Drupal GET form without tokens/op in one function.

mymodule.module

<?php

function mymodule_myform($form, $form_state) {
  $form = [
    '#method' => 'GET',
    '#action' => url('my_search_page'),
    '#token'  => FALSE,
    '#after_build' => [
      function($form) {
        $form['form_token']['#access'] = FALSE;
        $form['form_build_id']['#access'] = FALSE;
        $form['form_id']['#access'] = FALSE;
        return $form;
      },
    ],
  ];
  
  $form['field1'] = [...];
  $form['field2'] = [...];
  
  $form['actions'] = [
    '#type' => 'actions',
    'submit' => [
      '#type' => 'submit',
      '#name' => '',
      '#value' => t('Submit'),
    ],
  ];
  
  return $form;
}