Here's a simple way to look at central banks, monetary policy, and interest rates.
Interest rates are an effect, not a cause.
- If central banks increase the rate of growth of the money supply, ceteris paribus, initially interest rates will fall.
Call that effect "the liquidity effect". The central bank floods the money markets with liquidity and people try to make loans, offering favourable terms.
2. If the central banks maintain a higher rate of growth of the money supply over time, this will lead to higher rates of inflation. Eventually, higher rates of inflation will lead people to expect those higher rates of inflation, leading them to offer and demand higher interest rates in market for lendable funds. Call this effect "The Fisher Effect" (after the famous economist who first wrote about it, Professor Effect).
In general, central banks cause interest rate movements by what they do to monetary reserves and the money supply, not by what they say about interest rates.
For more detailed descriptions and analyses see this by The Grumpy Economist.
So why do we have low interest rates now? because the US Fed pays interest on reserves, sucking tonnes of reserves out of the monetary system, offsetting all their grandiose efforts at quantitative easing.