Custom Post Type only show for 1 category

Hi everybody,

I want to create a shortcode which retrieves the latest post from a Custom Post Type (CPT). I know the code below works, however, I now want to only retrieve the above if another field called ‘category_type’ is equal to the word apple. Is that possible? Thanks….

function show_casestudy_category1_callbk(){
    ob_start();
    global $post;
    $args = array(
                  'post_type' => 'casestudies',
                  'showposts' => 1
                  );

    $query = new WP_Query($args);

    if($query->have_posts()):while($query->have_posts()):$query->the_post();
    echo '<div class="wrapper">';
	$categoryinformation= get_field('category_information',$post->ID);
	if( $categoryinformation) {
	echo '<div> '.$categoryinformation.' </div>';
	}
    echo '</div>';

    endwhile;endif;

    wp_reset_postdata();

    return ob_get_clean();

}

add_shortcode('show_custom_casestudy','show_casestudy_category1_callbk');