SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4b32c20785a6c311d4a9ffbc9ce37ada72663bf238811ddb1fec0b534269a584' 
  AND token = '9v7JBPKZZtkSMzo1LqKwhDFB2xOVuSpWGtzVBJH7aJM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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