SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd45f65449460964bd01d95eb3cd13802a5fb404b2e22a09f4d1cf28c129d2807' 
  AND token = 'MHgM3/EDcVEJhdJy7CZq0RmsDp+vAaflIYgcj8jcCXY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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