SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '907f7413a899f8821e9cf76d60e80abb85c743aa5d881496f5936a8740e2ddfd' 
  AND token = '7CjSN+MtKMWNpSz1h1m4V3LchEWX5Y6GZq7WL5jqBPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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