WebApi routing started to work after I’ve changed the position of Register api method to be above of register routes:
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
GlobalConfiguration.Configure(WebApiConfig.Register);
RouteConfig.RegisterRoutes(RouteTable.Routes);
BundleConfig.RegisterBundles(BundleTable.Bundles);
}