SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6f70736da16c1ac4906776e9e48b81eec63d2fe61b66e8f3194e25f1cc1a9dd' 
  AND token = 'gySDKBAPvIGtIYd4FeevZTESQx6er71TWTClmRpzrKc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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