SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9cb76317adfed333575411c15608d6f272d26c70fd73cf753e18a54cf9275db' 
  AND token = '2TySRi42jTPzzbLTZ8vR8Kgv3qtwj2vFJww3ju7jeRg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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