Unset COD Payment Gateway on the Basis of Post Code in Woocommerce

I need to unset Cash on Delivery payment gateway on the basis of post code entered by the customer on checkout page. Currently, I have created a shipping zone with the list of pincoedes and I am using the following function to unset the gateway: function conditionally_remove_payment_methods( $gateways ){ // Define Zone Check for Pincode $targeted_zones_names = array('All','Zone 4','Zone 7'); $chosen_methods = WC()->session->get( 'chosen_shipping_methods' ); // The chosen shipping mehod $chosen_method = explode(':', reset($chosen_methods) ); $shipping_zone = WC_Shipping_Zones::get_zone_by( 'instance_id', $chosen_method[1] ); $current_zone_name = $shipping_zone->get_zone_name(); if( in_array( $current_zone_name, $targeted_zones_names ) && WC()->customer->get_billing_postcode() <> ''){ unset( $gateways['cod'] ); } return $gateways; } The number of pincodes entered in the shipping zone is around 15,000. This is causing the checkout page to load in 25 seconds or more. I need a way to accomplish this without slowing down the checkout page loading.