SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b2b429539f62b5d502c060978245b28de7be2926cd6453cb239a1154e8b91de' 
  AND token = 'b+xoBGHpStyoGWJTH3k3KZk+JZz7+TVwVwn2O5PjVDo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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