SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46cbc9a3e230ea4a73880aeb02c2a1b3a5c5fc9165a7d93b9f115d1d58d1e72d' 
  AND token = 'hniGRxI+Zq2399sxUCGZUWq1UudEYJYCczfW2X7Km6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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