Search result page – display values from the result’s metaboxes

You just need to get the data using get_post_meta().

<h1><a href="https://wordpress.stackexchange.com/questions/185685/<?php echo get_permalink()?>"><?php the_title(); ?></a></h1>
<span class="description">
    <?php echo get_post_meta( get_the_ID(), 'mobile_adv_service_desc', true ); ?>
</span>

This Plugin stores your values as WordPress metadata. So to retrieve the values in the frontend, you can use the built in WordPress functions for that.