SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f254f6eb97252756d1be1479643ff3856cb0901254f725f65494e8dba400ea5e' 
  AND token = 'mx/vrbs8zOuDM0iHI40dBvWSE9wZUvdJyrmuc0RoxzU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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