SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5493c377f80725c524be9852b65c3cf1a733ff2cbe0b39f1784b931c72d75818' 
  AND token = '1864MWdFAgAbHhPlwxFExG/nuockX9QKfOHanNOs7lE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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