SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'a2153be69bfb22b5abf97604ef7a89650a20bc96ed6d0914c4bc06faccc1e310' 
  AND token = 'bbFeTLA+KUTv7qfcByW2rhN9vPNyP8trxJprpfZe9sY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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