SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '735a0c333b0c3925c2ba0926ade88ffe5fc0e5843d79846c9ec48d9b20e8b554' 
  AND token = 'DDAj9hdDvcX8oJSDAx5ftfqkTGhx1gok+uSUg/0X6II=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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