SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94cc496d2e035dcc0d95e8994da9513b328b979ed22da8d9e0bd348d1e401354' 
  AND token = 'RaIN/Drh0y3kH3oe6lQCiPHA+5P3fu0bbk1ZiInz5Bw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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