SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5fe0937f1cfd566191eda8829d53b62a4f18b95d9617e94e8d04064c62082fe' 
  AND token = 'QzjNobCY4lAkvfnUAzIjg/rlDrXowyPi0sUKVKgoo7k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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