SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b203f07e23a8988905a7a186534820897d4c134760c89f68c5ac5176c6f5bf3d' 
  AND token = '0529B4ZwFzmOyO/eVGCb33JSvBLrv3zZVhLYkuG6CMI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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