SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '680b0895cc1489df89bcb432cee802a1fe26a2dcaa4ebfe42fd28b9e28ccdc88' 
  AND token = 'Q8MOgWzEUbkBLTJKDvN2o0uNTEWqQ1mx8piTUbSqP6Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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