SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c8ccb4943d7f6a36d2eb96d083ef0cf0813f4558f5d2caec1160238f0eb12907' 
  AND token = 'bSe+O1rBEO3yHUuIBW+xZ6UYlU+xBU/k5ZIA0Ur7WU8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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