SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89379bc81a569640b5ff73415504622aac0cc3743602d97234bd0fe3cc88aae9' 
  AND token = '+EofkYiwgcpwJMhzrxrHEUeEnBbKv7R+U4Jr0+houlY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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