Fetch products if image is found in woocommerce and filter the products

Sorry for my bad english.

I have a big problem, I used this code in my website - fetch products if image is found in woocommerce?

<?php 
   $args = array( 
                'post_type' => 'product', 
                'stock' => 1, 
                'posts_per_page' => 9, 
                'orderby' =>'date',
                'orderby' => 'rand', 
                'meta_query'=>array(
                    array(
                        'key'=>'_thumbnail_id', 
                        'compare' => 'EXISTS'
                    )
                )
            );
    $loop = new WP_Query( $args );
    while ($loop->have_posts()) : $loop->the_post();
        echo get_the_post_thumbnail($loop->post->ID, 'shop_catalog');
    endwhile;
?>

But I can't filter the products, have some variable to I put in orderby? I can't put this in order