SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df586ee402c0d773bd9c3aa54ffb9f7341a34172ef9d9ac2845a0898f651341f' 
  AND token = 'sLaDQuD2IJWkr/z/YiRhzmAstDG8iqnMVTg5wD9SqMw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}