SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '7baa36f5ea516cb26da33bb39e4d6be1aae9b4efe348e2fbce9319c495743c54' 
  AND token = 'zkJh35yxWh1mWZyyJppDvOTrBICXOyVz55TA9gvz4gU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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