SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0e8634d9cfecace43bba873ca7dc42293c83d904ae3daaa895f84b824783c10' 
  AND token = '7wbu9DZQ+yGhlOBqAFqYVOzUSeW2IYBqhmpQIA53xTY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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