SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1edc579fed7a62d88f31b825e2773e314f54d84dfe52a2e23741b97e210e1b43' 
  AND token = 'TzMUuZkxau7twn+oxbzcpO8uoAAJGQa6GJYXNayZ8hM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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