SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cace3cf05d070f6b031b44e5cdf14d9ba887e60df1267238474ee27bef4b5d4d' 
  AND token = 'kfK7UkMwiBlgZlCuo+HSq1P/N9BpYJlBgvzljqBU6ks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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