Redirect to HTTP non-www to HTTPS www htaccess

The answer by Prix works. To make it more dynamic lets use SERVER_NAME and REQUEST_URI instead of a static domain name.

RewriteEngine On
#we replace domain.com/$1 with %{SERVER_NAME}%{REQUEST_URI}.
RewriteCond %{HTTP_HOST} !^www\. [NC]
RewriteRule ^(.*) https://www.%{SERVER_NAME}%{REQUEST_URI} [L,R=301]

#here we dont use www as non www was already redirected to www.
RewriteCond %{HTTPS} off
RewriteRule ^(.*) https://%{SERVER_NAME}%{REQUEST_URI} [L,R=301]

Try it like this:

RewriteEngine On

RewriteCond %{HTTP_HOST} !^www\. [NC]
RewriteRule ^(.*)$ http://www.example.com/$1 [L,R=301]

RewriteCond %{HTTPS} off
RewriteRule ^(.*)$ https://www.example.com/$1 [L,R=301] 

The only real difference here is that first we redirect from non-WWW to WWW then we check for HTTPS and redirect it.

If it does not work, try this one:

RewriteEngine On

RewriteCond %{HTTP_HOST} !^www\. [NC]
RewriteRule ^(.*)$ http://www.example.com/$1 [L,R=301]

RewriteCond %{SERVER_PORT} !^443$
RewriteRule ^(.*)$ https://www.example.com/$1 [L,R=301]