SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '298b3cc057268d9a62551fd1a06d9807987a6caa95c273377dc8def7ae6b600a' 
  AND token = 'D5R2v7rke/YisBIzjyYwHdj+udScR6qXnwNMevO8pSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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