SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0c95bde5f76174714851dfd7cef6bdfb2cc7c49f2fd3fbb65485121d84b56d8' 
  AND token = 'HmEkErlkpBqVLTTdVSJ7RMbDkiDNjmX67RVRJbRcnsI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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