SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2c765b0f789598828c79fdaae9b3140abf31e4dc1cb39934255fbb503784bdbe' 
  AND token = 'C1KJ6PjmC+gwF5NXihUTisCmP2mlOxcv+Y6XgS8nnqM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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