SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd7d00cd86746b30fe67cf147012bd7e732a80045da787c79cb46289c793789f' 
  AND token = '1NENwk5mLeLrQYRxiwvEOEZEoCcVjY0RV+zjzErTnqQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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