SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4685e9858f71e46276b092186d516d67f5cb4c268803b64a8e34cf9eaa641f6' 
  AND token = 'Cje79uhS6/pwEW35Fnjb/NVnpT4c0p/Ho+yDm2V1sgs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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