SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba5c608f416acb768f195693999d6b04b994eb554b3e84876ce22d4ffd02f540' 
  AND token = '/sgBLI6nVgtPVaDBQFLVDjeFDbRWdIkXZ32c21OD0iY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00085

JSON explain

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