SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a66adda231b077741e71b228fde7ace65182edf11f439a84d8b209d149fbb36' 
  AND token = 'LzLHuP/EzW1YHtNvX42vwfxR78hsrkTbgjb/N0+Hetc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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