SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f554177a197e38a38f21b9c30232064c4bca1526f72bc3e689b76865faf84bdb' 
  AND token = 'fsLjqFpzog5eYY67ork8l6xLJqRDLn6M04b3+KawHgQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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