SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d7052a245948d533f67ee58e6a81cb37f0915a69dad99f2f24f133595ad5e81' 
  AND token = 'CENquSdNumD27nRoggpSJBu7d7WnE/+kuKD8nXpuqIA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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