SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04868b9003387a6ba8a7cd5d28098ef4d61e6ea2dd9d038bc94bd376cac23320' 
  AND token = 'tdGf3lvWl8wYMF+ToLgktXwn8KDLJfBFAWaiZgTZpoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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