SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46f76c2ee203295faf3d1c7aa65b717a36ee92386e9e62606a91524134b34184' 
  AND token = 'tBfso1BXmq5WVXbsxxbFwQAdUQEtvvQTliwxFgpSxtU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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