SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd3844fecf121be4812150a24bb36ee7496503d1e8555fce7b244e95089c036df' 
  AND token = 'SqTNuVZaW1QDu/L5a7lMjvTgb3EUvEbaHHQ7u9NuBKE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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