SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfaad0570fd9e2296fa446141a3a73afba868011172d1e709f11aa419af4e05e' 
  AND token = 'dWssksk2en4Gp7OjEBw0kTTSt9O4yP7CpglB5LFk1bA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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