SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40dbbc35717f054d30f92880b2187cb7632a249496e013f52f74165871264a97' 
  AND token = 'Hc5GESwRD8iN40xrdcIyFfb3vO/xo20LZ67YtckwCfQ=' 
  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"
    }
  }
}