SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c467a9712ac480a6b320f73fd6c449aaa435ea030fcf5d1629503016188ba060' 
  AND token = 'BbuSb3rsryGr7dPN+DnavAD1xBOdkZwnd+p4qCJ/yLc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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