Why is the data from the database getting slowly?

Question

PostgreSQL

Please tell me, I use nestjs with typeorm postgresql database, I get data from the database in 150-200ms, but if I wait 20 seconds and send a request to the backend again and get the data, then I get the data in 1000ms or 1500ms, although in theory and in general it should usually be 150-200ms? Used sequelize, same thing. As if if you wait, the server starts to fall asleep and wakes up for a long time when a request is sent to it again. this is how I make a request to the database

async getProducts() {
const products = await this.productRepository.find();
return products;
}

Please tell me any ideas, answers, options why this is happening.