SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5745441e0502c99b052b59a977345dfae9265c7c456a9e4183863ccc0bc3d552' 
  AND token = 'xNNkmvbKW1rWDaDk5iKLVBhMnsbsdwExYUdURYxTUrc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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