SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2858635603b84593360a45ab989b77fb6ce57273654ed6085b2186acfd0f2e5c' 
  AND token = 'QiQFTipBbQGF4Vp1GmYDpndbIFP6Z7irzxo+ysSoOLE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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