SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a2c10bb50227d29dd4702c72acf522db06c7449aaa0d17679663a43fdcccac7' 
  AND token = 'DjGUDLGtDMlnxQYDjA8XpfoWhCbHZ1a/u2ghOgXZGao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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