SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '973384e3ed6f3b2b5dc79786c1075f6b08504c7688b14e3ae64c7188b377bf2d' 
  AND token = 'Uesfg2Xvzj2soTYhOlHUlzBNy/ZYT/kmeB+0ogcoduk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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