SELECT 
  p.product_id 
FROM 
  cscart_products as p 
  INNER JOIN cscart_product_descriptions as d ON p.product_id = d.product_id 
WHERE 
  p.product_code = '24MRC224DPLY40-LED' 
  AND d.product REGEXP '^Small Mr\.'

Query time 0.00117

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "p",
      "access_type": "ALL",
      "possible_keys": ["PRIMARY"],
      "rows": 2465,
      "filtered": 100,
      "attached_condition": "p.product_code = '24MRC224DPLY40-LED'"
    },
    "table": {
      "table_name": "d",
      "access_type": "ref",
      "possible_keys": ["PRIMARY", "product_id"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "ref": ["cscart_migrate.p.product_id"],
      "rows": 1,
      "filtered": 100,
      "attached_condition": "d.product regexp '^Small Mr.'"
    }
  }
}