SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1237e15fe020c75f87ed2503b798efbb9dae7f4ee9d85f4b116fa5817371d09' 
  AND token = 'zRgw4/hxilsrl/LDyuYOots5T/xIQ4VGo5hBsOrTszE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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