Is there any known way of lowering lag

You only connect to the servers to find games (or when you're hosting, to upload statistics, but it still shouldn't affect your game lag), so your connection to MW3 servers isn't the issue. It's all about finding good hosts. There are a couple of things you can do to help finding less laggy hosts:

1. Make sure your NAT type is 'open'. This means you can receive incoming connections in addition to sending outgoing ones (NAT types 'moderate' or 'strict' do not allow incoming). Try this link or any of the ones you find on Google for instructions on opening up your NAT.
2. Pay attention to the ping shown when attempting to match games. It starts out trying to match < 50ms ping games, then moves up. I usually bail out and try again in a few seconds or switch game modes if I can't find a <50ms game.
3. Geographically closest hosts are generally the least laggy, so try to play at the same time that people around you do. Usually this will be between 5-10pm local time.
4. Unfortunately it's harder to match games if you play in a party. More people in your party means more free slots have to be open, and there are always fewer games with lots of open player slots. Also, hosts that match well for other members of your party will not always be the best match for you. So if the lag is really getting to you go solo.
5. Use a wired connection to your router instead of wireless. This will help eliminate packetloss on your end.
6. Any downloads or web surfing or anything that uses the internet connection will contribute to lag on your end. Unless you have QoS set up on your router AND at your ISP endpoint, which is never the case, extra traffic will affect your perceived lag (even when your connection isn't saturated). So avoid having other computers connected to the network while you're playing.