SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '461434539c6aa7c0ab3badfec20c8b2363e36af0b36016b00b6bd81c48d6880c' 
  AND token = 'TkhpCUunnukyCnDr0FOf6psh7LYWSh+OJwrNsQDrTs0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}