SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '125908d5a0d9797d642c62bf02a82e9d964b3d9205e8133196b340b0e3704b5e' 
  AND token = 'IO4qwwPXrnUnUXrLIB/0r9fViVTKGIZjDRxivb3zMZI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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