SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '610a101d085b3181fb629ac838df4bbe56f52081c195a819f688a37a0e2375b3' 
  AND token = 'Mtdcq1IrXEV0kz5tTvaRi+RcsQnx5Qh56YxnjmxZEX8=' 
  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"
    }
  }
}