You could use IF conditions to add the parameters,
$args = array(
'post_type' => get_post_type(),
'orderby' => 'menu_order',
'order' => 'ASC',
'posts_per_page' => -1,
'no_found_rows' => true,
'tax_query' => array(),
);
if(condition){
$args['tax_query'] = array(
'relation' => 'AND',
array(
'taxonomy' => 'product_category',
'field' => 'slug',
'terms' => array($category->slug), //Supply the current product_category terms
),
array(
'taxonomy' => 'product_locations',
'field' => 'slug',
'terms' => array($current_location), //Add the product_locations term
'operator' => 'IN',
),
),
}
else{
$args['tax_query'] = array(
array(
'taxonomy' => 'product_category',
'field' => 'slug',
'terms' => array($category->slug), //Supply the current product_category terms
),
);
}