SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    1533, 3286, 65, 6093, 5546, 2294, 6089, 
    40759, 37772, 1473, 5916, 40554, 47165, 
    47166, 49394
  )

Query time 0.00205

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": 15,
          "filtered": 100,
          "index_condition": "cscart_products.product_id in (1533,3286,65,6093,5546,2294,6089,40759,37772,1473,5916,40554,47165,47166,49394)"
        }
      }
    ]
  }
}