How to set up a redirect in .htaccess from index.(php|html) to root?

Question

Apache HTTP Server

DirectoryIndex index.html index.php

# -- INIT
RewriteEngine on
RewriteBase /

# -- PRODUCTION
# RewriteCond %{HTTP_HOST} ^www.assist\.loc$ [NC]
# RewriteRule ^(.*)$ http://assist.loc/$1 [R=301,L]

# -- SEO index.html // index.php ??????????? DONT KNOW ????????
RewriteCond %{THE_REQUEST} ^.*/index\.(php|html)
RewriteRule .* / [R=301,L]

# -- HACKING
RewriteCond %{QUERY_STRING} base64_encode[^(]*\([^)]*\) [OR]
RewriteCond %{QUERY_STRING} (<|%3C)([^s]*s)+cript.*(>|%3E) [NC,OR]
RewriteCond %{QUERY_STRING} GLOBALS(=|\[|\%[0-9A-Z]{0,2}) [OR]
RewriteCond %{QUERY_STRING} _REQUEST(=|\[|\%[0-9A-Z]{0,2})
RewriteRule .* /index.php [F]

# -- DIRECTORIES
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_URI} ^(.+)/$
RewriteRule ^(.+)/$  /$1 [R=301,L]

# -- FILES
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule .* /index.php [L]

Please help me figure out how to correctly make a 301 redirect from the /index.php page and the /index.html page to /.
** Now I can either completely redirect from any address to "/".
** Or again it turned out "/index.php" - a cyclic redirect.
** I tried to make a redirect directly from the code, but if the address is like this, but the framework cuts the file from the query string if it matches an existing file