SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a508eb8b74d1b5c56e44d42ad4684f033a6303329d612ad904669d4cc890c21' 
  AND token = 'XqyZHHQ7/gyln7/ynkF+vQ6rO6JKhBKMzvUfnQIetJU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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