SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b402c50d8dde45faca8915b677eb4adeaa1451e0cd1d8a8bc9e49763a3f7c8f' 
  AND token = 'BtnfintCzYTrDhgVlunPlJiEya99/Q9Zf0efmlu2Ilo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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