Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8db2182b2b3840e812ef7ff65d58c0aeff4570e6efb20e531646b81ace3d191' 
  AND token = 'MyohU+zYhpKyd1MM7TZXQI5SCKvXe1+5wmxcOefQTHc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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