restrain filter on get_the_excerpt to queried item in stead of current post

Looking at the documentation for the get_the_excerpt filter, we can see that it receives the WP_Post object representing either the current post or the post which was passed in to the get_the_excerpt() function call.

Thus,

function q_excerpt_custom( $excerpt, $post ) {
    if ( get_post_type( $post ) == 'post' ) :
        $excerpt_custom = '<a class="card-permalink" href="' . get_permalink( $post ) . '" rel="nofollow">&nbsp; HA HA HA </a>';
        return $excerpt_custom;
    endif;
    return $excerpt;
}
add_filter( 'get_the_excerpt', 'q_excerpt_custom', 10, 2 );