SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '90bf336babd79bcd1456bb4cb194d674d4a8d6c3e22b7bc636b3174370ac05d6' 
  AND token = 'isnk7Cva0jgKiXeWj/SOKRlBjwqIWbxEv4GV9rIJOQM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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