Custom Loop/Query Based on Custom Fields

<?php
            $args=array(
                'meta_key'=>'readmoretext',
                'meta_value'=>'Go check this out',
                'post_status'=>'publish',
                'post_type'=>'post',
        'orderby'=>'date',
                'order'=>'DESC'
            );
            $wp_query= null;
            $wp_query = new WP_Query();

            $wp_query->query($args);
?>