SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '267e69299a0ec33bd6ccb41571cb33052e92837211e56e30aa51f9a80994ae8c' 
  AND token = 'KPCliTkbXeXosD50XatAVClTIN5uyL07ZJhKBtp/wvA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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