SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '362b19ccb6858c6d2df7f4f934685e8a6f2bd3dd95742903ca6b99747472767c' 
  AND token = 'FDn/pIoXrOYgSke7iMfrFVxzv5aQtOzQyraSIJm/ihQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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