SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1055ab17a157a3448f7090d8bafd134f48d4ac3e107535b2daf5de7eeb8d75c9' 
  AND token = '4HEYSyHGIFWA2J/WywGxP/gDIVNQ0LbchLkWN+WtLN8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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