SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb178d895b50ed007cfaf552eec1bd03d4e375b67a81ca1a1651eb3ac9369ec9' 
  AND token = 'UyIxGZXM+n3DxbsX8lZESIMW2kYHKdfEkvjfmEsmHHg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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