What does it mean to say "the locks were beautiful and the keys were beautiful and fashionable"?

"In the past, the lock was not for theft prevention, so it was beautifully made and the key was beautiful."

By contrast, we can now find that people in the past didn't close the door or pick up things at night, and even if they didn't set heavy shackles, they wouldn't lose things. Nowadays, with the rapid development of science and technology, people's psychological defense lines are getting heavier and heavier, and they generally express their nostalgia for the past slow life.

"Once Slow" is a poem written by Mr. Mu Xin, which is included in "Larks Call All Day".

Original poem:

Remember when I was a teenager?

Everyone is sincere?

Say, it's a word.

Morning train station?

The strip is dark and deserted?

The small shop selling soybean milk is steaming hot.

In the past, the color of the sun changed slowly?

Cars, horses and mail are all slow?

Love only one person in my life.

Is the old lock nice?

Nice key. what do you think?

If you lock it, people will understand.