SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '092a91789fd676317986cfebd38ddfb084f4d193dc40afd32cb3554f5ad3f587' 
  AND token = '6zDm/OuoFt8/jUpGj4aiNhRV/lwF4evoslZc/6Gl6CI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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