SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e72bb35f5a94df54b78e2395362e672471a589d365502abe5f964f909c7fb21' 
  AND token = 'B/d3XOeehHdD5rBjQ7gzLV4sIowgL1GtZioMqT+oqNU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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