SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be6fb551c0431d3aa4db19ea9967e54515c17329ec44ddc5b2bc2461279b2a6d' 
  AND token = 'se9qaPqnsFnJDxWkC7qX0sE01A7qHPeBO8QsSy2Cj6c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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