SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e922b4d741b0fb461144e49285e56a093eb6c7b85b737c15907fd6365e3e9320' 
  AND token = 'Fgy3lqqgv8oLGbCQSpaRBOfpc3TEqYKyqVKWdIf+RFs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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