SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbf686fc5cdebe8df79dc584fcab5eaefe88d75c2ec9db068ab87f9f6a936ac5' 
  AND token = 'eGO7qLnxbsi/7wqJT6dDBwS3RXhrcA0oYbrB0zq4m0M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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