SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '86bb3daf6e78190e7559423a00a90bc30051a0f204756faf789a5213237c9bb5' 
  AND token = '5Zajgk+aRulqLNCHGDhbo5JsXEgEK5PiioRuP8PZumw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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