SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0b5dbb944a9a0d126afebe770c2291199ca255e3eeb140da3ef89d91a047efb' 
  AND token = 'uYueAJhkWD9wKlSWstcLdKQt3PIPS6uAeLQpXkdxQeA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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