SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3732bb7c8d9f2a84b81790cc8db133067970bfbb6f632303e295760320a2c393' 
  AND token = '/67XV9RlqUCsXFpzOBG+EWKeTYo6RDjXyApyO82g9K8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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