SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '886f7f7b8291dd99e71f6089c3dc7eeb35d5c7e5ef2e031b12873e161654c981' 
  AND token = '5brxBe38ilV2iMY7cupahcKJZ+HSDrCmaNGR0Pyi9Ng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}