SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30f5107972023902fda7538cf1c0dc4813cb61005343a05b8c8892d5b2a2a266' 
  AND token = 'PUcITQSU/dQD8qUiRzEv37xy6t3RLcdJZpmwxMfiAis=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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