SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd157281086cd8d379df7fe0851f1f92950787b21d869fca5cffe2022dd75aa0d' 
  AND token = 'MQoYUuoUOuv/sPgVEK80XphPRnzSr3A1Ofgu9a8Qs2c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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