SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb243f89af467440ecaa7802eb7d39e5b4599608423efdc8e243e2539cc26a19' 
  AND token = 'bxjW3vUtoVbncfuSrBiVTR4H4tJDxhjnyHfayEgE9LU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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