Why doesn't Lighttpd cache the .unity3d file?

Question

Lighttpd

Hello!
Installed the server on the hosting. I posted there a small unity3d application in 56mb. Set up lighttpd.conf

$HTTP["url"] =~ ".unity3d" {
        expire.url = ( "" => "access plus 7 days" )
        setenv.add-response-header += ("Cache-Control" => "public, must-revalidate")
}

But it is not cached. It constantly reloads. It's all worth it on Ubuntu 14+
Has anyone come across this?