Hi,
A "Display the results" action won't delete any products.
The only action which could delete the products would be a "delete the elements" action.
Also, your filters are not correct. product_sale_end and product_sale_start will never be null. So that would actually mean selecting all the products.
Now to check whether you lost your products or not, open the hikashop_product table via your phpmyadmin. There, you should have one row per product/variant.
If you don't have anything in that table, then the products are really lost and you should use a backup to restore the products data.