SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae139d4519164238d195177aceaa20fe3c036fd12dfad9af13184d5ee63a3e56' 
  AND token = 'cQnghPiM3/qut6wSTu5/L27rqJH+9LexRpqAGBvcsa8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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