Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36c84147ceef6c6eedf662ce1ed208828ccbb9b4f278d83d0a6a8dd4a943b837' 
  AND token = 'erTdJVgm9Nv8QWA08cIYhXgv4if3DceaVkGtjgYA+dM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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