SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b6853ef7a3e63cdfe235ca03668c076e626a71aefa8e3993b74cf5c69a3d63af' 
  AND token = 'Ck8xmIYPz6ahPMGd19td9SBXRUNnIUcbsu0ZGjnRc6Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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