SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99a58e2587b9031cb09dfbcd855d171e38e73d9aeb1cec0aa11829360267081b' 
  AND token = 'RU9jyXNXU2N+XqTPaUxOr2xrxPp01HD6HEwPzq5zfWg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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