SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'efc1e2b7492865fa57f1df31de3f2c4bbd5cc3a6a43ea6dbc96ca22f4ee904ae' 
  AND token = 'GhOHNVIlEKrEUlxxb2ceIkDmE9FOCEi4+nbnJrIAnOM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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