SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2697da9fe0faeb0232b01b79caf9a4c3d0478b2324263566c1d10f33e3a851a1' 
  AND token = '4+FugwuXKd6yXStHjxSaEev4YgWZ3KK1Y8rZ+mZhKK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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