SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24de468c052704d6d5b2bff85186c794175fb30be082fbf4b7f1c756a7a984e9' 
  AND token = 'WFaWUqTxAfjC5TKXJLopTyJt95fzvCrfzNoMtb/gVTc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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