Opencar 301 Redirecting issue with ?route=

Opencar 301 Redirecting issue with ?route=

I have restructure the website from WordPress to Opencart and so all URL
has been changed. I am trying to redirect my old products page with new
but it is not redirecting since OpenCart adding some weird ?route= and so
on..
Here is my .htaccess
RewriteBase /
RewriteRule ^sitemap.xml$ index.php?route=feed/google_sitemap [L]
RewriteRule ^googlebase.xml$ index.php?route=feed/google_base [L]
RewriteRule ^download/(.*) /index.php?route=error/not_found [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_URI} !.*\.(ico|gif|jpg|jpeg|png|js|css)
RewriteRule ^([^?]*) index.php?_route_=$1 [L,QSA]
Redirect 301 /store/products/old-item-name/
http://store.mydomain.com/new-item-name
It is redirecting to this weird url
http://store.mydomain.com/new-item-name?_route_=store/products/old-item-name/
I appreciate your great help.. million thanks