SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5b7768fea7818bde8145ba1b7d02eff72502e93582c5db3dc1f2a38f32a4966' 
  AND token = 'JzgbKpSqAmQTAxqEMFXBxJx0JcjeiNKMcU+Dq71G3+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}