Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91cd7795198825fb1b4cada10e4afdc0dd568cec2fc606594b382c521e8863fe' 
  AND token = 't/kCBqiIiB/ILRqC1LEKt+zwNYfXLrBJEDGSSPyTx8E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}