SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b229b0d417192bf17dfc63376cf2558c82b886f58506d62d376248f6234475e4' 
  AND token = 'Z9uN+oe4tjpnVGNq/WxtaAri789uT9ffigjneNNCv24=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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