Yes. When using the IS widget, the Add to Cart button is displayed by default on your front-end when the feature "Show products instead of variants" is disabled in the Search options tab.
“algolia_instant_search_product.hogan.liquid”.
At the bottom of the template is this snippet:
[[^ _distinct ]]
<form id="algolia-add-to-cart-[[ objectID ]]" style="display: none;" action="/cart/add" method="post" enctype="multipart/form-data">
<input type="hidden" name="id" value="[[ objectID ]]" />
</form>
<p class="ais-hit--cart">
[[# can_order ]]
<span class="ais-hit--cart-button" data-form-id="algolia-add-to-cart-[[ objectID ]]">
[[ translations.addToCart ]]
</span>
[[/ can_order ]]
[[^ can_order ]]
<span class="ais-hit--cart-button ais-hit--cart-button__disabled">
[[ translations.outOfStock ]]
</span>
[[/ can_order ]]
</p>
[[/ _distinct ]]
For your active theme, click on "Edit code" and look for a file called "algolia_instant_search_product.hogan.liquid".
This file is responsible for how the search results look.
In this file, look for and comment the code starting with "[[^ _distinct ]]" and ending with "[[/ _distinct ]]".
I've highlighted the relevant portion below: