SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '817ac364e5c7c4bbe03dc32202fb384bc7f845a83daecbcfbb4c2dbc6c1dc172' 
  AND token = '8ZM198gSOgAr61QuMK22CUloB4JVyT4uA+GVPx/Z7OA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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