SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35fa211e8d3b9a97a25951ba3e155728495167a3999eb0902c26d14455b83a0b' 
  AND token = 'D8kFRP/l5eA+LBjDUphiXQtN9JUQh+3THnQVUekrWIU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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