SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae6a5a3ecbe9502e5aa431bb4e3b7052dae263fbf20814d880cd19103ca76e7a' 
  AND token = 'jBlobC0Je7waMl2erjicQWj7aA8/bg0wZFXO+fXbHHo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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