SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '83126a472f30f63309ae8292aad85804b4131fc9d5abbfdc162cb0b8b232a8be' 
  AND token = 'XOktZmmxvQFH+sed3u7QJD5pGet5/IxZRuoRwbeAILY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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