SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1646cfb8c659b248899d80b8679c229735c9bfec692a4667bf9110b620cff8bb' 
  AND token = 'pifwT+8QoHAbmwR0CN1Vg7OlHMU4DYUM0zHi8VlTiKM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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