SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    20591, 4247, 2912, 3006, 1043, 3449, 
    4299, 41594, 6044, 2460, 20588, 5998, 
    3437, 2018, 2443, 2497, 2511, 4045, 
    5416, 5418, 3448, 3196, 2911, 1661, 
    3223, 4074, 14985, 2466, 1056, 36492, 
    3712, 5402
  )

Query time 0.00189

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": 32,
          "filtered": 100,
          "index_condition": "cscart_products.product_id in (20591,4247,2912,3006,1043,3449,4299,41594,6044,2460,20588,5998,3437,2018,2443,2497,2511,4045,5416,5418,3448,3196,2911,1661,3223,4074,14985,2466,1056,36492,3712,5402)"
        }
      }
    ]
  }
}