SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8bc42ad41ae8aed9cb9c53cf77d249cd3095b4cf761c338820f85d7986673e8' 
  AND token = 'vBVz8MhZJP2dKQNggBWCWx1tgRuEnZSqVdBnlp7VIrU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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