SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac345a9c131ae0de70b3347ead6d591a685044ef9c6a56c8d8c4b8056cc86a31' 
  AND token = 'xJ+YAfqqpRX/Wgp/WD/YsCGwvj4ZkHYvqC8rm3CmWQU=' 
  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"
    }
  }
}