SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0745ad3202e8f9e1de45499b54dbb2f1639860381e4ab8c50635556facbbebf3' 
  AND token = 'dHwII2ZZhp5dWe+bz6LjHHo3yF/w+UjRirToZDNU7+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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