SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd3b7b21d5fd1704bc6a705332b39617f445ee0045f6d3ee21ed070ddeb28b3bb' 
  AND token = '8IdkivZQ75E1e7w27t02pBaLPr1wuGDVI/5sHgi/kBE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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