This code can help you to reproduce the problem:

(ql:quickload "hunchentoot")

(defvar *acceptor* nil "El acceptor de hunchentoot")

(defun inicia-ht (&optional (port 4242))

  (format t "Iniciando el servidor en el puerto ~5,'0d~%" port)

  (setf *acceptor* (make-instance 'hunchentoot:easy-ssl-acceptor

 :port port

 :ssl-certificate-file "./server.crt"

 :ssl-privatekey-file "./server.key"))

;  (setf *acceptor* (make-instance 'hunchentoot:easy-acceptor

;  :port port)

  (setf (hunchentoot:acceptor-document-root *acceptor*) (pathname "/var/www/"))

  (hunchentoot:start *acceptor*))

(inicia-ht)

ab -n 1000 -c 10 https://localhost:4242/index.html

ab -n 1000 -c 10 http://localhost:4242/index.html