SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18fddc3e555f5573bdacd03f561865206fa1a4c5e05f45a5a7f1ac4990418d7b' 
  AND token = 'zxfALPdwihGqVs/pkC/MYClNpjtsYgU/3nM5zKx1VXk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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