SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '534227b8b0c806d7ba8159ad96bddadac4dc8e3d474a6089511c910658362b3d' 
  AND token = 'jG39Ux4A8tv+WsqapUWi+X8vFxF2W3dM/C93CRyW9Sk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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