SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b8457d7a02fef153ee6b34f16a74f46c8c3b22eec79d006b5b53e6a6554c488' 
  AND token = '9guGgOwzuzKAXhu/91uVKtBj6pTtC/qUsexXMqtrcB0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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