Use the --timeout flag to change the timeout.
--timeout
herbie shell --seed 2019088 +o rules:numerics (FPCore (x y) :name "Euler formula real part (p55)" (re (complex (* (/ (+ (exp x) (exp (- x))) 2) (cos y)) (* (/ (- (exp x) (exp (- x))) 2) (sin y)))))