SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dd1a5d27bc720636bda35eb8e673b88294d5fc2a8f801d0817fe53c262b7541b' 
  AND token = '7vbEb85xzngGJbdETGesNfj0vd2YQO/kUfzfUT5Mrbo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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