SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30a5d87a62536b33bd0ee6ffb11821f869b7835469c641ba6494f9ea8d9ad5de' 
  AND token = 'x6xp4FjxGzxEbjZaWu/qA2v5MrvYzachZNhRw5g72rM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}