SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '094c628ac861cec05772f28547401caf9d6c7c82b0fff7927b7c26708dd133b3' 
  AND token = 'CXj1QhZ+W+LXOlcSZ2skZiOsOimwM0Qb8FnxWYkiuVo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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