SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84fef06a7e959ebac0b84f98153bc56981c429ab28f38b50333d463cd479d7bc' 
  AND token = '1sE3lCc1Cpuaz7171Hz8DdTsBAk5yHzZMCg63A7BnwU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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