SQL syntax error. However, it works normally at phpmyadmin

) bracket missing in last condition. (i.e AND (b.meta_key = ‘usage_count’ AND b.meta_value=”0″”); )

 $rowcount = $wpdb->get_var("SELECT COUNT(*) 
FROM $wpdb->postmeta AS a, $wpdb->postmeta AS b WHERE a.post_id = b.post_id AND (a.meta_key = 'customer_email' 
AND a.meta_value LIKE '%[email protected]%') AND (b.meta_key = 'usage_count' AND b.meta_value="0")");

echo $rowcount;