SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'a8c957fd5470a8d11a3737782fe87019f34bfa678682cc7bc4b29f3400ffec81' 
  AND token = 'IS7HOZYci/NI6kn8oPFnINpRvIAFH8kYTr/SQdnXsas=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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