SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d4d62c5cd5158042436ae135e758f947d2941eb22323e67093b4aa52f6fd9a6' 
  AND token = 'yZX2q8qrJFzzl+meLCryUQxk+jQ6qbpCu8eFtfx+0/k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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