SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b03f99deed69153688f0f42b872854507a5724a1e403763746f5acd77d2364f3' 
  AND token = 'tmCx/FRy61CHmamVTtRx6eVJzSzKCGP3e3QJfcjbaVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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