SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '905fe469982cea10eee295563da3de314a869de9a8852ecd265c297f4b53ce27' 
  AND token = 'WOknqMtOEUW+dn+ZMDxGUNdLeOpiWH1PHnRsJSzJ8m0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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