SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    2070, 2078, 2108, 2136, 2215, 2245, 2271, 
    2276, 2309, 2310, 2392, 2399
  )

Query time 0.00075

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_products",
      "access_type": "range",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "rows": 12,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (2070,2078,2108,2136,2215,2245,2271,2276,2309,2310,2392,2399)"
    }
  }
}