SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fedea516fab7b29e9756e1e3ab53e795d3453dc0a31f4b8d9ec9b9378ea55ad' 
  AND token = 'tmuMOcejIQDgUtWy1qhTyXEoGa8/HxJWJhqCFDa5wew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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