Can htpasswd be used to restrict access to a URL rather than a specific folder?
From the docs:
Require Directive
Description: Selects which authenticated users can access a resource
Syntax: Require entity-name [entity-name] ...
Context: directory, .htaccess
Override: AuthConfig
Status: Core
Module: core
"directory" context means that you can put it in <Directory>, <Location>, <Files>, and <Proxy> sections. So, yes.