SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6aa2cfef45e0d910ee5c448c8e25326449adffbb93045edd0cee56db1e50b688' 
  AND token = 'HPCydirupJ0P5BbTqAtH4I7oClEQ2ONkwue9VY6QrX8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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