SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b6ac4ec05df77a8caad13d1bc2bd76ef731abf92ba8d84b46c745a662e10af3f' 
  AND token = 'qZrON8LY9O/mnqAItGZ3iY/tgCQ9jyisxqHfqEoyC5o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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