SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28880ada771d152dce66290246ea1434996a658086db984dc7d9b2bfc570462a' 
  AND token = 'cfOssS/iOgl072KGOlj/S9ykboM8MnCOKk0P/Bt9m4E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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