SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c88fcfed2a95b2438111ddd810d7d7678d43456373ca5a684386d55898d2a97' 
  AND token = 'msbomQVV+HqWx7kl/g+aHTBbfz4L+1FQipPN0pXdGZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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