SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dcc8a80f83003cb2bf4fae8cdf4c39aa7d4207339951ff1004ae41ba38826b82' 
  AND token = 'SeDKTDUJi5VuZVQps90XRqm8K1IduuCeA9h2uPNhnvM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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