As this is a mountain bike, the fastest tyres are probably those most appropriate for the surface you're riding on.

On dirt trails, you need grip to accelerate, turn, and brake. This is often best served by wider tyres with tread, which are slow on paved surfaces.

Riding even well-finished trails on slick touring tyres, which are far quicker on roads than MTB tyres, is slow going. I've done it. The lack of grip means slowing down more and earlier, and sometimes some wheelspin when you pedal hard. 

Fairly smooth gravel is somewhere in between, as are gravel tyres.

If you've got a mountain bike and you're using it on the road - perhaps for commuting - your biggest benefit will come from using smoother tyres, though most of them are also thinner. Go too thin and the tyres won't fit the rim well. For typical hardtail stock wheels, slick tyres in the 35-45mm range will make a big difference, 50mm if you also want to handle rough but grippy surfaces.

Rather than concentrating on the brand, the specific model of tyre is more important. All the major manufacturers make knobbly tyres, road racing slicks, and endurance slicks. I have Schwalbe Nobby Nic on my MTB, and Schwalbe Marathon Supreme on my endurance road bike, sticking to examples from the brand you have.

Pressure is also crucial. Silca have a [pressure calculator](https://silca.cc/pages/sppc-form) which is worth a look. Note their disclaimer - if the calculator produces a result outside the manufacturer's specified pressures, limit yourself to what that manufacturer says. This will still tell you which end of the range to inflate to.