SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '253a925b91490216a78f2f6b0bbd10ba09fd846528a0ee8c3c6c6820b3398e3a' 
  AND token = 'YKNGGw2rSwg/90LHpysVDJy1fL30YzQ4BKy2fsNKKxA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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