SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f49aa94a9f94ce59d19ec70d39b9faebbc54255e9bcdf58c7653a55cf26bb34e' 
  AND token = 'Qn6oQLwLbGI5MH/mlbAvyIUIfBag9Knazs3g2kUkZeo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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