SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b33159bdb06c7155904d34a1b911628098faedc7478ca0742ab4a606a72409d4' 
  AND token = 'NAMgt4E+Ot7Z3LHgi7BSYg5LTMVlQzYYzCIMsZYXVpg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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