\[ y'(x)=\frac {a x y(x)^2 \cosh (x)+b x^3 \cosh (x)+y(x) \log (x)}{x \log (x)} \] ✗ Mathematica : cpu = 3599.95 (sec), leaf count = 0 , timed out
$Aborted
✓ Maple : cpu = 0.091 (sec), leaf count = 33
\[ \left \{ y \left ( x \right ) ={\frac {x}{a}\tan \left ( \sqrt {ab} \left ( {\it \_C1}+\int \!{\frac {x\cosh \left ( x \right ) }{\ln \left ( x \right ) }}\,{\rm d}x \right ) \right ) \sqrt {ab}} \right \} \]