In this paper we presented a method to build a kinetic model for hydrocarbon pyrolysis from Molecular Dynamics simulations that can be extrapolated in temperature and in time. This model was trained with 6 MD simulations in the range 3,100-3,600 K. This model was shown to make accurate predictions on temperatures up to 4,500 K and robust predictions on temperatures in the range 2,800-4,000 K and with different starting molecules (i.e., chemical composition). The range of temperatures for robust predictions can be easily increased by adding more data to the training data. Indeed, this range of is increased to 2,500-4,100 K when the number of training data is doubled while keeping the same temperature training range. Extrapolating down in temperatures allowed us to reach timescales of microseconds with the KMC simulations in only 30 CPU-minutes, whereas this timescale is not reachable in reasonable time with MD simulations. The predictions of the model were in agreement with experimental results and we were able to give for the first time, to our knowledge, an estimate of the time before equilibrium for different hydrocarbon pyrolyses at different temperatures. Although this method has been used here to investigate hydrocarbon pyrolysis, it could also be adapted for any condensed matter simulations such as surface catalysis, biomass combustion, and electrolysis processes.