SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9be773dbf09d1ebc9966f5beadfd0a4bbf2e1a845b19c59cad7879f732db65fa' 
  AND token = '+VIHqOQ0VGwNe0y4YUS7n6zKVjCfsat7vNLYb4qZ4aU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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