SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a322d14052605f93ee6c3624fde531041eec9fb136054ef41a66e12d3a38f1d6' 
  AND token = 'uO+vv2AFYPBamwPjTj4fNvVxwkgCvTH48Zhmxod/t8w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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