SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1671e00c6dbaab68991b264b7306c644ae91531a43e3631fd6f29cdfc33a6c3' 
  AND token = 'MAl3rB5Du7p6NcWe7/4xomjXVjGbaVWngIyKcBCzAsQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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