SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5283aba7c8ea70b77d16c23632e37f93a8f5cdd17f34061b622df87ec66298bd' 
  AND token = 'Jtsx9GEhlSf+V82s7xvK0fkZGfFfrx6ylA3HaMb7Mkg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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