SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84282db54da61b1b25736dbc4665bad9cdbbe39967d4a61cefe4f58d194d9ebf' 
  AND token = 'hnFssPmIfBUuDCccMKna0/uGUzBBY1eg7OPKpw0swnA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00099

JSON explain

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