SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a5b8094b2113d48f51e471d9aa400be779794add44d5c2cc95f17a49e2317b4' 
  AND token = 'mDQAi/BHamnmzLuoJbYQErzBWdjpCbaMkY9NpdICy7A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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