The most recent official poverty estimates for Kenya come from the Kenya Integrated Household Budget Survey 2015/2016. However, these figures only go down to county level and counties are too heterogeneous to be used in targeting a response to Covid-19. It is unlikely that any new poverty data will be released soon so we must look back to less recent data.
In 2015 the KNBS released a report Spatial Dimensions of Well Being in Kenya (warning large download size), which provides ward level estimates of the % of the population living in poverty, based on the 2009 population census. Whilst Kenya's population is highly dynamic and the distribution of poverty is likely to have changed since 2009, it is the most granular dataset currently available for modelling the distribution of poverty at Sub County level.