SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49d26ec7e6fc94224661e7eb70c585413321fb5ab9e20bd8ddb10b644f6427a8' 
  AND token = 'gp3KfVNJ/pUsKD8HwHueJhJJroKNKuaR2LVfjtsXQYc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}