SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '722d948caca16a30c2eae527b423383d8f10c34137bdaf83b62ccfeac2801223' 
  AND token = 'Ll4HtUnidhcK6aSoZLnRnB5SHxZBDPU2nV4Gzkr48js=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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