SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad57f20abec63bd46d52bc703d31c79ad054b6bc60977fdb726bfff62a6b6180' 
  AND token = 'bXHHBCREK9KAvTv3nwF9Pog9WcNnLOlHK51VY0F8FAs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00066

JSON explain

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