SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'de07c0be149d07c3d895c4038f456aa5da99fee9cae949471202eca703d56f39' 
  AND token = 'h9VzFoKy/Mbyns3lZhqeX42Bbhj3dKVUEBAwZtgVywM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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