SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    5300, 5297, 1103, 1102, 1104, 43834, 
    1105, 1107, 43825, 1106, 2620, 47567, 
    48837, 49710, 50295, 50304
  )

Query time 0.00165

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 (5300,5297,1103,1102,1104,43834,1105,1107,43825,1106,2620,47567,48837,49710,50295,50304)"
        }
      }
    ]
  }
}