SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '15dc8d6e05d66b4071a29674be5e4e7b993486a976a203ef6e91ffb2214c4658' 
  AND token = 'zw2/5C7Wq/CJgkXVGA4cFec/X8F1jlLu25/9NwKVrrU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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