  ALP-mediated decays and other as-yet unobserved $B$ decays to di-photon final
states are a challenge to select in hadron collider environments due to the
large backgrounds that come directly from the $pp$ collision. We present the
strategy implemented by the LHCb experiment in 2018 to efficiently select such
photon pairs. A fast neural network topology, implemented in the LHCb real-time
selection framework achieves high efficiency across a mass range of $4-20$
GeV$/c^{2}$. We discuss implications and future prospects for the LHCb
experiment.
