SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dfb0800496fd9bfe9aa131079e0c770d73305427b73035e8dd59819139311467' 
  AND token = 'rpJ30hoy64xvfXBSPTNvsScpKg5gQepkT0UdQZEOorg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}