SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02a63c961e6b09a394f67effb788d0f703a8991246adc94ba30e9da34e3c4a64' 
  AND token = 'LtRt3CZCQ59hVvUwVsXvFPhXa6A4W8Pqx9X2+kovbUw=' 
  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"
    }
  }
}