Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c1d6a72f66d21a32063c589568c8ac70ae91c55dcffad65c97e5f504c2c8182' 
  AND token = 'C+92UJ0Sol4SiuLvp5Hp2HnZHqWA4qfRmL/Z8zP7GDk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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