Cache in a collection implementation

MysqlCollection.php

<?php

class MysqlCollection implements CollectionInterface
{
    
    // .. other stuff
    
    /** @var CacheInterface */
    private $cache;
    
    function findById(ID $id)
    {
        // this will make a cache key which makes sense only for the rest of life of this object
        // if it is a singleton then any sequaential requests will not query actual db 
        $cache_key = $id."_".spl_object_hash($this);
        
        if ($this->cache->has($cache_key)) {
            $response = $this->cache->get($cache_key); 
        } else {
            $response = $this->mysql->find($id);
            $this->cache->set($cache_key, $response, "60sec");//will expire soon
        }
        
        return $response;
  }
  
    
}