SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'c9ff9492a8ab87383543379d8bd0986925baa4bfb72898e6a92e95d89d48198c' 
  AND token = '8F2KJU9HrxQBIfORr06kXzWjJwec88EqsO0/1bxUZhY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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