SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '52704aa8c42e771f23d629ebd3c9f3b59dc38c7acde7199d310f192fe99e7e7f' 
  AND token = '4QOVf6PNdFQbHwgxdAXBJj4aPAz8Dj1FH3AhdMuHXaI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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