SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42e3a116da5d800d2d95afec85ab5e462980d006940e87ed9755f88d1c271027' 
  AND token = 'FTw7TEe65ZMfEQoWcT2q7gUKWh0YJ5r35IUjk5JWbNs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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