Рабочее правило, если кому-то понадобится
# check that there is indeed a query string
RewriteCond %{QUERY_STRING} ^.+$
# check that it doesn't start with one of allowed parameters
RewriteCond %{QUERY_STRING} !^(utm_source)= [NC]
RewriteRule ^(.*)$ /$1? [R=301,L]