SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e67701d8a88fe4876222df4fb8d2532cbf5a0fdcdb018e35fb2d466e477fcdb' 
  AND token = '/ztJtN+tGYF1SUmnmWQiDuwx+kBuFAI0gpvJ0sKDE/I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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