SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b2bba9892f6bf38844bd698119afe8e17d1e6f6ef783dff190836cb386a3577' 
  AND token = 'wLqlHe/N8zeSqlz5up3zYNJoqOC4QhXFofHHn4BfBgs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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