SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c7958c0b81a71942a9c60351458af8598dbc01278509b40f0b11d0889819df7' 
  AND token = 'neFbpoEJRuw9V9xKaMkg2hdWVYUdTyMAnyyT8RjXYGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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