How can I enqueue comment-reply script only on certain page?

Try adding the following code and let me know

if ( is_singular('1740') && comments_open() && get_option( 'thread_comments' ) ) {
    wp_enqueue_script( 'comment-reply' );
}

I think the conditional tag which is comments_open() is not required. That checks if the comments are allowed for that specific page or not.

Try using the following code

<?php
if ( is_single('1740') ||
( !is_home() || !is_front_page() || !is_single() ) ) {
    wp_enqueue_script( 'comment-reply' );
} ?>

comments_open() requires the post ID for the specific posts to check whether the comments are allowed or not. So avoid using the condition for that.

Don't use is_singular() with ID as it checks if a singular post is being displayed using the post type name as a parameter. Instead use is_single() with using the post ID for which you wish to display.

In your above code, the flower bracket was missing too for the if condition.

Hope that helps the question you have asked.