SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '687bee9bf4711856d8925fc60f74644bc7b4328282152f607bc5b0d98c9036b6' 
  AND token = 'UrWzNf8kH1YpfY3+oO7aqRJhFUA92ZFf3lHgrg+B5eM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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