SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b2712b4fe6e71eaa8b1956dfdd39dff87ef416224876a85b3d62afff5ad59dd' 
  AND token = 'IeLZDlBa4eDuDn44REXqplneZtIStex3EB4MbtCHewY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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