SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '613f4c4da0f679f5f506c04694f3ef0fb67cccd5f823f83e33ebc2eab65dfcf5' 
  AND token = 'YOHnLjtywJ2FxTfh5zJqnayMkHqku7lb3glX9i+5Y/s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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