SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46fac3c60eced3bf8579be96ce09d13e970a788ef0a15ca548f31db2689193f4' 
  AND token = 'LRY0zMgu6n51I/SU+vSijZqFrGYBIDiqt1l4EgxpO3Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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