SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23c5fb28ef701011637c322d5990d70868e9baaa63c7d22325878ba9cf5ba761' 
  AND token = 'BlHGNXUak+CjF/5itBT0xGWHs4tK61Hw4myz2rDUgOo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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