SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87a9dc031232245c4bbcdfd38cbffe86c8e289225ff4b67046cbe08d1fab50ff' 
  AND token = 'cFyiL9DVKXWSjl0Pk3YGuDA4N8GjN/14CzWF//06bQ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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