SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '557c8d6fbf8bc237b251c7cc1b3eb76485f79b394fb6f8071d3924b605701b8b' 
  AND token = 'GW48MXvVpc1JjhgbaSN5eXUGN2LgR3lDd+q6/E/tVEU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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