SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '033cc1ac409543df747be0857faa75910e8213637cfe61a8d37c94673d9f8102' 
  AND token = 'HykXd4+Zloq0tOVbBmYjFZZzR1puAZfOXU/PofyxLeA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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