SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    21639, 18958, 22905, 18981, 22906, 18982, 
    22907, 18984, 22909, 22048, 22910, 
    22055, 22911, 22052, 22912, 22054, 
    23988, 22064, 23989, 22063, 23990, 
    22062, 23991, 22056
  )

Query time 0.00115

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": 24,
          "filtered": 100,
          "index_condition": "cscart_products.product_id in (21639,18958,22905,18981,22906,18982,22907,18984,22909,22048,22910,22055,22911,22052,22912,22054,23988,22064,23989,22063,23990,22062,23991,22056)"
        }
      }
    ]
  }
}