Datetime comparison issue, timestamp set to true

Dear Metabox. I'm trying to set up a comparison datetime, so as to only show current or future events posts. I'm failing and not sure what I'm doing wrong. I'm presuming the 'timestamp' => true, option has been added to metabox.io for precisely this particular sort of comparison, but I can't get it to work. Any help would be hugely appreciated.

My reasoning as follows:
1) the datetime meta_box field is set to save in the database with 'timestamp' option

            array(
                'name'  => 'Date',
                'desc'  => 'For events over a stretch of time or taking place on more that one day, this should be the END DATE.',
                'id'    => $prefix . 'event-date',
                'type'  => 'datetime',
                'timestamp' => true,
            ),

2) Second, my query

If my thinking is correct - this should return posts with a date equal to or greater than the current date - but no show of any posts.

<?php
$type = 'npl-event';
$key = 'poetrylibrary_event-date';
$today = current_time('timestamp');
	$args = array (
		 'post_type' => $type,
		 'meta_key'    	=> $key,
		 'meta_value'  	=> $today,
		 'meta_query'  	=> array(  
                   'key'     => $key,  
                   'value'   => $today, 
                   'compare' => '>=',  
                   'type'    => 'NUMERIC'
			  )
	);
				
$homequery1 = clone $wp_query;
$wp_query = null;
$wp_query = new WP_Query($args);
if ( $wp_query->have_posts() ) :

/* Start the Loop */
while ( $wp_query->have_posts() ) : $wp_query->the_post();

etc…