SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4492a6a142f5b20943b3850886a15884813f2d4cbcfb78c5032a9e1fa7e257ca' 
  AND token = 'FnN/zgTXYhztubcSB0bV6KAO6M3bsHOdY4vx6AjfRT0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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