SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad193e1bd45fc42c08404896b3aa91c579f1942696e9b6609cc0f1b5c2245b26' 
  AND token = 'wBYMt7B29pSMeCDfqj4xXlMcXSATBkMO7X0llSTGiNs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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