SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '53bb3e0e60d31aae42269402ba13ecc7e80d48bcb7ea6b74247f0cfbf47f3916' 
  AND token = 'DttM6/+/DdooPmFy3wMaIlqJrROqNURJWyYUspAjCwA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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