SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cbed4ab64dc258c91c65a8aa6b23e94e68afe9cbc0d274216ea2103a4cbc1319' 
  AND token = 'hKVimciBa15p0DeJy2iZlPqW4g+54tgJRXFEjv/0Jwo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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