SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ec22f50b4665b629f36de85b3ee0e9ed7451f12a8c4a042685ceed8b0306af1' 
  AND token = 'wOGbtD9x33IaPGXXyY5RHaMLwAEbsZmx/ISWzuQmQEA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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