Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9db2830adc7eaf7aeaf629617f6684d05820cbcb2412e7a1dbc5ec7c8b0d98c' 
  AND token = 'eBdHc1pzJWMw55XHFZ+tocosUdNiSgdWjGpayUh+vKc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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