SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dce7eec4334cc3d962ac634ca50cecca666a27ca4966faae9ab0221ae49a4f9d' 
  AND token = 'jII/50zrWkiuQLzWnitc4qRQN8C8Pe8ynUnjIKGcTD8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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