SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '07f64e8388d6f9de5916270cea9eb4df692124aaa27eb7d5db1e9c7b3941737f' 
  AND token = 'navUPikYZJLqYmkXt7e8I8BehDMHc5xgxCOH8+UBw0s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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