SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd804c3ba9fc21bedeac78d4d24c6dc2ad521ead36169e85a92710352a11d47a1' 
  AND token = 'kHqSb9KHdnSIN5cBGjtShMNZD3ZHWYYuzanFdsGCsh8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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