SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e424c54538940ad5d57031f2e80379067dfb0e2b4757a81c5c8700216e9ae8e1' 
  AND token = '2ZW4CmPPz/WbO6ZNqxbwhF/u5KUuJKHwlQCLcM0jTHk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}