SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '283ed85eb72ef372a7e31d9fe6cff8acdc191331e5cf948203d6258807f93959' 
  AND token = 'axM89KmXOVc8fUFm2AWqiqUHesygxpGwq1hUD0zuieY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}