SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bbcbdfec5194a211802d5fdc1ad0eebb6bf7519b219289a158fe61272ae1fe2' 
  AND token = 'NILWkp9QPxYjh3yOYz50ZIiVLH0/hC54ek6BElRakoA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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