How to print a pdf document with mupdf

Why not remove the password temporary and print the resulting unsecure pdf with lpr:

pdftk secure.pdf input_pw own output - | lpr

If you don't want that this command is listed in bash command history:

set +x history
<commands>
set -x history

OR

<whitespace><command>

OR use a script (adapted from here):

#!/bin/bash
unset password
prompt="Enter Password:"
while IFS= read -p "$prompt" -r -s -n 1 char; do
    [[ $char == $'\0' ]] && break
    prompt='*'
    password+="$char"
done
pdftk secure.pdf input_pw "$password" output - | lpr

Source for disabling bash history

There is an PDF pager based off of mupdf that has exactly what you want: http://repo.or.cz/w/llpp.git

(Some unix OS'es might have an easy way to install it, for example Arch Linux has the package in the Arch User Repository: https://aur.archlinux.org/packages/llpp/)