SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    1949, 1924, 1947, 1906, 1946, 1945, 1944, 
    1943, 1939, 1927, 1942, 1900
  )

Query time 0.00095

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": 12,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (1949,1924,1947,1906,1946,1945,1944,1943,1939,1927,1942,1900)"
    }
  }
}