SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a02d2f9fb21913e007c8fc6aa7128a219f3a1f783daef130b56e9b7511413768' 
  AND token = 'GfDfhuQOhnQBchnv4BIApKx+lxk1lUoRliWm46IZKIY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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