SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec0da41c831a22692c63d539e63ec4ebcebd616421d93bfc9090608a04e8a7c2' 
  AND token = 'bpP1eliKb7JA6wZrBzYguNRVEg5VZ2uMQl9Sn+emsIA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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