SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6001ee0af7379f2ed4e848396c1e0d974944c13db2a63d24fc6e160d3473af0f' 
  AND token = '9xnlXXmrOk6yMJZNjIHDEtzCJDpsuLsJY+Pm7bs6TXI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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