SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '992b4cfc8edadf898c5bea9cd6522fffc5a592a7ca548e5538075072f31d323f' 
  AND token = 'ABiq5h78fSZvxXRHCEed61OgOaJnBw2NrvGa+D556jM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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