SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4148ab2d0a7d32b6440cbe144ee5afe26ba91defddd990ee847ab9f52753838c' 
  AND token = 'xivlNK84k4hWPYTmdwki0QmbM/FSIz/PnIa0P3Euugg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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