SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1c8141120815ba2c93b15ad3b1f0a8e287791ca312c4de9d9acda9079484156' 
  AND token = 'jLIaXQPAWzcQiexNHDZjyTQJXxfOK+fGeudK0Tw5uQY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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