SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94f5b34acf12429494adf7ea53d636179c0a72a745e3dd25893e28884193517d' 
  AND token = 'O/2WFL7cEmkdbalh/v5ILIUMO8dajLSM56J/fPBecSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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