SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a292935314b484e9a96c6682d61cfda7451354e8d0b48e12f28d5fe4c9780d27' 
  AND token = 'GjrCQSoMYNLVC++E1O3ZNeYpyxTDdbwy2lxya4HUnTI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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