SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'caab094e66dbf6e97f950d8d3edff47d8f339c35feed5f88e2b08495e732586c' 
  AND token = '66uQZnwnMY9ThtVfF+QnBYgvHLV462fVz/uY2JA8TrU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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