SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b979e44fa311c4d8d22b4ffaf39e5554b860921059f4ed41a23d6be8a09d4924' 
  AND token = 'GLy1dpfvJccoowH0/FeeB+xkDhgqpOkP07UKAO8qqXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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