SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8769d406c66d9a4948d6ba9a72342495cade73b8583abdde275fbc12da9313c' 
  AND token = 'TQ4IAphYCDErLk1jw9fG/zEX9f64IZs8eWsZJKqEc+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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