SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae3466747fa154af98c384f638320495b481feca75e0a733669bc08d16b9eb31' 
  AND token = 'OVFUMarH5lM7jN3O9Jxhx8V0ra356YntiiESSK/PtDg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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