SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14036675a89b83064b1e0e661c4ae83cb28a41f234e6b986fc1744170dcc5478' 
  AND token = '8PgLAgxXCpGGUuoZ1FCJFYaAmR7tvci99+pwT9ku5jw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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