SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9a1626dd52345631cb067309362ad233cdfe732513402345fc5eb665dbb3fd37' 
  AND token = 'DLxQZ1OEBd2RRj3tGSxOZuqost/CSGPka1lLyIIJqrI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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