SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '7346309935878f5ddd761b98060b21cdea5b23ba888981cda57b21407e8b74ab' 
  AND token = '8K+VlBHCK7hsduy/5GxuK1piai+WubNUKsn8DsCVBUs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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