SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5962afb329c9a39b870685bfa2b0393e93f653836dab47fc3177c183a95739dd' 
  AND token = 'nABQZxuN6uLNjdAkQD58Sh7oQuCsE71eA60INroXlxc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}