SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6cf9b1f74611399285d99dc614e67dbe4644690327a8f935d066856ec78a8a37' 
  AND token = 'Jq8fzmTkIpitMZsny/xNK47VO6jpg7JGaGbV2c4bFH8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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