SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    9889, 10475, 9890, 10483, 10495, 10490, 
    10469, 9877, 9894, 9891, 10480, 9893, 
    9878, 9886, 9882, 9888
  )

Query time 0.00039

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": 16,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (9889,10475,9890,10483,10495,10490,10469,9877,9894,9891,10480,9893,9878,9886,9882,9888)"
    }
  }
}