The microlensing event OGLE-2017-BLG-1434 features a cold super-Earth planet which is one of eleven microlensing planets with a planet-host star mass ratio $q < 1 times 10^{-4}$. We provide an additional mass-distance constraint on the lens host using near-infrared adaptive optics photometry from Keck/NIRC2. We are able to determine a flux excess of $K_L = 16.96 pm 0.11$ which most likely comes entirely from the lens star. Combining this with constraints from the large Einstein ring radius, $theta_E=1.40 pm 0.09;mas$ and OGLE parallax we confirm this event as a super-Earth with mass $m_p = 4.43 pm 0.25M_odot$. This system lies at a distance of $D_L = 0.86 pm 0.05,kpc$ from Earth and the lens star has a mass of $M_L=0.234pm0.012M_odot$. We confirm that with a star-planet mass ratio of $q=0.57 times 10^{-4}$, OGLE-2017-BLG-1434 lies near the inflexion point of the planet-host mass-ratio power law.
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