SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1813b56756cb691099a8b5cafc9390b75c7a514cfbcee6b5f732d3bbb709cd2e' 
  AND token = '7xn0hPPh3m+4zmfTpsvZ1reS0Y/ocx/xayRjRfob0uE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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