SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68d3a05347741d772a8d83f4699dd23babc0b968c95ff48852850626b8eedd1a' 
  AND token = 'aQdaXKpxF6FaS7OwLZBY1vUYWTmqtgGoJyBZWZYbqOw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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