SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02bf57825fb4181b53b2011f7915c086e885f43626463e6905a05f4708cab9f9' 
  AND token = 'lbpR1sYms2bCY4mXMUxaSM9eqccnCzk8HnVlwjiVeQk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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