SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e677f839aab2b82839c785a79228ccc2d2ddfed8dfb7f4c07801fdd662804690' 
  AND token = 'JndVxmileaekWZPA6aLQT7k+XfvV/IYoGDiff+bBKsw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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