SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd17a3520b7d88fd562a460a80665ad3723fad89ee45e41516b17a9abdb589289' 
  AND token = 'iiQdZAd0yWIOypUitd9MN4oG5tR9Cp1wioze1GKEQac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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