SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24250bcd38a927b0f89e38cc2f705d9cc0198994f5c2688cb717721acb8796a9' 
  AND token = 'zIzWIH6eH73q3fkFhhd24ziVzS2tVunT+rcmTEdZcuw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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