Try this
global $wpdb;
$results = $wpdb->get_results( "SELECT * FROM $wpdb->posts WHERE `post_type`='post' AND `post_status` = 'publish' LIMIT 20" );
foreach ($results as $result) {
echo '<div class="card">
<div class="img">
<img src="'.get_the_post_thumbnail_url( $result -> ID, 'thumbnail' ).'" alt="">
</div>
<div class="info">
<h5>'.$result->post_title.'</h5>
</div>
</div>';
}