SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5741ebdb5d7935c7ab788161631013d1f1af94f249fc2e7917b71dd102aa54e9' 
  AND token = 'gFOU278bOVIhAq/XnymMJyVxhXnYtG0PiV5hy2Rpb9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}