SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    48559, 35175, 47657, 2695, 319, 35249, 
    47902, 43852, 36305, 48220, 47606, 
    40310, 22020, 49105, 48652, 49009
  )

Query time 0.00134

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_products",
          "access_type": "range",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "3",
          "used_key_parts": ["product_id"],
          "rows": 16,
          "filtered": 100,
          "index_condition": "cscart_products.product_id in (48559,35175,47657,2695,319,35249,47902,43852,36305,48220,47606,40310,22020,49105,48652,49009)"
        }
      }
    ]
  }
}