SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7bef04af707dad4a2bed0c5d81d5a4d7fdd5dc3b658cab479f6b888de8d8f780' 
  AND token = 'd6GN/K/WO9bzZRvZr7K4WjcGQTREudTw32CF31zUOhY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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