SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cb4572ea589a691af03f85304be82ddb42d1dcb2275995692cffc3096b30bec' 
  AND token = 'ridpZqD3SUFeEeqjeJEKBPmYA9G2xyPJeIHseSzAqJY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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