SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '345c2784b6a09a31d9116fbf3e9afc9dcf95777668489331859059fb6fd376b8' 
  AND token = 'UBXsCvW++pd7yE/fmJbd5uwYL7OOmBuVWnQbCX+l8X8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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