SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cff8ea404c191584de2eca67a49fc4980e26ea7ad63473e7579f42fba0555e78' 
  AND token = 'ZF6iEQS8Sde5pueCElHn6DD0XDzjTVZQlOUyETYltU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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