SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d89e14c4ee250cd4eced7235718c08cc2387c847e885f94e0c34044db6e5f6c' 
  AND token = 'yN8SSRhE9eewi4WCTdtHhcE1wlOXjqsoEeKQ0ycDdSw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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