SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd96bba7879690b982f6d5f106e2a52815efebfd9666b9ab1c5be1dce20ab38f' 
  AND token = '4jM4mrUdlfkSV8A28CIrQKXMwFq8BkXRliKyVHkmIxk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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