SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34a1d1c2d4a7fdc9ac07c862025bb4f450872838dff819428c92569d7a6412d8' 
  AND token = 'WTZU/FszMNCR9vM/1EJSwSS9vNECn85wwj/mQqEK1WU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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