SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    9894, 9891, 10480, 9893, 9878, 9886, 
    9882, 9888, 10482, 9776, 9777, 9781, 
    9775, 9778, 9779, 9780, 9782, 9790, 
    9787, 9791
  )

Query time 0.00047

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": 20,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (9894,9891,10480,9893,9878,9886,9882,9888,10482,9776,9777,9781,9775,9778,9779,9780,9782,9790,9787,9791)"
    }
  }
}