SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '769184e58adabe0b37854ea835f548db28c3d06e1a96c541372ede7c1697b6db' 
  AND token = 'EvFyOkDJNcqDT4pFDECF7ohjlrlrrEzWOBYmrcGzHjA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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