SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9f8157929fb0830797041faf7ea1f80c8996ea7558ac9ded64311120bcdca87' 
  AND token = '4uH+1WCoJxlFVmwlUo/HNEJTO2zafvhPo/XgHmEu7qo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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