Check for specific Product IDs in your cart to return true if they are there. WooCommerce/WordPress

functions.php

<?php
/**
 * Check if a specific product ID is in the cart
 */
function wc_ninja_product_is_in_the_cart() {
	// Add your special product IDs here
	$ids = array( '45', '70', '75' );;

	// Products currently in the cart
	$cart_ids = array();

	// Find each product in the cart and add it to the $cart_ids array
	foreach( WC()->cart->get_cart() as $cart_item_key => $values ) {
		$cart_product = $values['data'];
		$cart_ids[]   = $cart_product->id;
	}

	// If one of the special products are in the cart, return true.
	if ( ! empty( array_intersect( $ids, $cart_ids ) ) ) {
		return true;
	} else {
		return false;
	}
}