  Sgr A* exhibits flares in the near-infrared and X-ray bands, with the
luminosity in these bands increasing by factors of $10-100$ for $\approx 60$
minutes. One of the models proposed to explain these flares is synchrotron
emission of non-thermal particles accelerated by magnetic reconnection events
in the accretion flow. We use the results from PIC simulations of magnetic
reconnection to post-process 3D two-temperature GRMHD simulations of a
magnetically arrested disc (MAD). We identify current sheets, retrieve their
properties, estimate their potential to accelerate non-thermal particles and
compute the expected non-thermal synchrotron emission. We find that the flux
eruptions of MADs can provide suitable conditions for accelerating non-thermal
particles to energies $\gamma_e \lesssim 10^6$ and producing simultaneous X-ray
and near-infrared flares. For a suitable choice of current-sheet parameters and
a simpified synchrotron cooling prescription, the model can simultaneously
reproduce the quiescent and flaring X-ray luminosities as well as the X-ray
spectral shape. While the near-infrared flares are mainly due to an increase in
the temperature near the black hole during the MAD flux eruptions, the X-ray
emission comes from narrow current sheets bordering highly magnetized,
low-density regions near the black hole and equatorial current sheets where the
flux on the black hole reconnects. As a result, not all infrared flares are
accompanied by X-ray ones. The non-thermal flaring emission can extend to very
hard ($\lesssim 100$ keV) X-ray energies.
