SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fa4b5c32e9759f2afa67454fb276c05e92a87c596c1a00d70be2533c0e209126' 
  AND token = 'fU1oNA1SZojWIgs/ywrimjVwKONcQ40JWag8OKnNh+s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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