How to remove one of the arguments in a request to nginx?

Question

Nginx

For example, a request comes to nginx
site.ru/?mvx=34234&rty=23423
Moreover, the values ​​of the arguments can change.
How can I remove the mvx argument with its value from the request and still keep the other arguments?
I understand that rewrite will help here, but something got stuck with writing a regular expression.
It is necessary that the site does not know at all that this argument took place, the argument is only for nginx.

Answer 1

Try this, haven't tested it myself but should work.
And yes, I know that if is evil :)

if ($query_string ~ "^(.*)mvx=(.*)$") {
    rewrite ^(.*)$ $uri? permanent;
}