SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '71b617b6c65fc9eb23ccc4d97423d9869041c9056b64a70fe5fff4f6ff0bb60f' 
  AND token = 'rIszO58k+FmvwbK6ZNI3LmPiVMyZahr7N9HHIGD3ohc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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