SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc5bd58efe4a9f52d88a6fbd1c0e2c17ff293546559cc6a205d1201ef4da8da5' 
  AND token = '/hUvGzIq9guGTaNdgq2BRoR3bVKxb5LbPBOotGFxZGw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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