SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b88ce331f8b76584b6f2b36917977e88100733a51711c7037c177b71bcab3d56' 
  AND token = '4iSC9xVWExWyjwg6F1xUnrpEK2IX6fAX4UU5HVgCOJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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