SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c357e217272ba43585ec6606ec9fe43b41cbae4ff8fd6eb7efdef9e10a72bc50' 
  AND token = 'Dm7z34G38Id6iYkxV7EF14oCFU7fy8JKGqhFneaaj9o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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