SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '81566df79cd96cdd574fd49c830570f88591f7d6d304802d41f3e9efc6b66de4' 
  AND token = 'pgKS0VmEZOgKjeweaZj90xPC/gJ4GlqXe0HVx28XuZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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