SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45695002d9ff933e65b848f6113f47c556e97f55171d0e5ad7df1aaab1bd698e' 
  AND token = 'IpFyFW07kUDlnyC6lRH6ihSwimkoI7ggmh9nkEmirLc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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