API result formating: How to get rid of row tags?

General questions
1

I am preparing custom API plugin.

And I putting arrays to the return expecting such result:

<result>
	<status>200</status>
	<message>Custom message</message>
</result>

pushing:

return array(
    'status' => "200",
    'message' => "Custom message"
);

but I get:

<result>
	<row>
		<status>200</status>
		<message>Custom message</message>
	</row>
</result>

When I try:

        return array(
            'status' => "200",
            'keys' => array(
                'status' =>"status",
                'result' => "message"
             )
        );

I will get:

<result>
	<status>200</status>
	<keys>
		<status>status</status>
		<result>message</result>
	</keys>
</result>

without row tags

How should I format return to get rid of row tags?