SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b24033c3650186265edf974d12954b75fd15ca2aecf632e9969a4afb3223b2e1' 
  AND token = '0cjXTfD82/OHSfwdkVJXyLZZpb05njMk1miR+G3TZ0U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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