SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b4f3850e2ef75c528cf14d9761afa01a4100334b4e4f9e105cc5447aec471ad4' 
  AND token = 'MO4p+g1sNfILBt0eS064ISuvuJUaYx7ja+3LNWrUmOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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