SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '182c84d0bfb61211a2711f8973d50164499f1430ca5a40d068436a9c3b4b1cf0' 
  AND token = 'dMa0qKwdYvaNj/zMYqGXJh+sH0fRb3JI7vpZYrU68Rk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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