SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5d7fc4ea93a357add77c772a63cff09dd749cf1f1cfa2cf4253e5fa01ad01ee' 
  AND token = 'FOhl9qujlqNcMu/7uHxxKs0GbFLeSu/INHrxVyfk6vQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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