SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7c6ca79fc3ae6d5fdfae0c00d8d7fcc9d0c273e9aa16a76474d8994b19a6701' 
  AND token = '+3OajAr10lWRqQjxYjq6wEb++QSTdOhRuyXQrAHLWvc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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