score:4
KLM sells connecting flights via AMS with as little as 50min connection time, so making such a connection will usually be fine.
Assuming that this is all on one flight, your luggage will be checked through automatically, you won't see it in Amsterdam. As you are going from a non-Schengen country to a non-Schengen country, you don't need to go through immigration. I've connected via Schiphol many times, and only had to go through a security checkpoint once (and that took no more than 5min).
You'll most likely be fine. And even if you do miss the connection, the airline should be able to get you to London not long after anyway.