SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd61ade03359a8eb1b473fde6113cfeca3f617c6bca531146b43c3329781e23c6' 
  AND token = 'v/lxIDaDRtOzK8+X/bu/7H9R3jMO1XSpAuBOBdjKX1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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