Output Total Number of Locations from Store Locator Plus Plugin

I often use Store Locator Plus plugin to have a store locator on a site. This time I wanted to show a total number of locations present in the locator in my theme design.

I’ve made a shortcode to display locations count in a widget. We put this into child theme functions.php

// shortcode [totalLocations]

function locations_number( $atts ) {

global $wpdb;

$table_name = $wpdb->prefix . 'store_locator';

$atts = shortcode_atts( array(), $atts, 'totalLocations' );

$totalLocations = $wpdb->get_var("SELECT count(sl_id) FROM " . $table_name );

return '<strong class="total-locations-number">' . $totalLocations . '</strong>';

}

add_shortcode( 'totalLocations', 'locations_number' );

Use it as a regular shortcode anywhere: [totalLocations]
It works with latest WP and SLP. I thought, maybe to add some cache option inside, but no success yet. Any ideas on how to improve it?