wordpress-meta-query-multiple-keys.php

<?php
$meta_query_args = array(
  'meta_query' => array(
    'relation' => 'AND',
    array(
      array(
        'key' => 'city_name',
        'value' => array('New York City', 'London', 'San Francisco'),
        'compare' => 'IN'
      ),
      array(
        'key' => 'featured_post',
        'value' => true,
        'compare' => '='
      )
    )
  )
);
 
$meta_query = new WP_Query( $meta_query_args );