SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbf0674c0ee1636a896c70b260fa094486c5481b720cd157c9943a0b009bef3b' 
  AND token = 'vqdxKsmjYmqmP69GYpZ7LbOJS8e8j/NvmBsSoXKy5v8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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