SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a63b8b8040932836cb3c9962cbdbff125acd116b0ffa333ec4192b80b8eb09c' 
  AND token = 'GshJgEcWMWCAo6JWygbf2oJ9uKxTtgqnh5RJTVB4Gwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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