SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c695fddfd649d267263c1b067d6c26e397c9388a77e2283c749fb2134738fd7' 
  AND token = '1wwpwKTahPVYUiE9u/bqpuxVxQtqbs8x/YXzxhzPYQs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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