SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1cb69b66cdfd15ec99b05842b90728d6111d3ddce80844a5ed354d0b8dc793c8' 
  AND token = 'KR6bozvG0bztM3ZuerQYyh+RXHmFg40hS0wUQ4xqg2Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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