SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58f5fd0063492b1b17399101ac18711a2f54baa16b6130d574522f5695fba854' 
  AND token = 'j0rMlZN0r6ijA2tVcZ9zR/Y6yU9iTAjwtJDr2H5S/xE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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