SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f235e7b4af8355ac5359b3d3b20407ec19f87dd7114c6138fd40e34b2267cf4c' 
  AND token = '1ZWuqBwr97/xHd24YlPBF19wqIwRqaVsfPPv9QyppkU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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