SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1eacc3079d085984171b41a4429c58f69e0c23d6589c47c4db742c95da51e42' 
  AND token = '2qj+vwkr43qzSJFscb0gwmr2dEVlzunrq23lockX3KY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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