Recently, the XENON1T experiment has observed an excess in the electronic recoil data in the recoil energy range of 1–7 keV. One of the most favored new physics interpretations is electron scattering with a boosted particle with a velocity of ∼ 0.1 and a mass of ≳ 0.1 MeV. If such a particle has a strong interaction with electrons, it may affect the standard scenario of cosmology or be observed at low-threshold direct detection experiments. We study various constraints, mainly focusing on those from the big-bang nucleosynthesis, supernova cooling, and direct detection experiments. We discuss the implication of these constraints on electron-scattering interpretation of the XENON1T excess.