SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d7b4179fd9fa003ee2c2212c7abd779868b07eb835ebcf5ce69baad36fc663c' 
  AND token = 'GaLkUybxNluowLX4lgOVl6rT0t3zlc+vrdX/LGKRYag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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