SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '845dbb5ba3ff949b40da2984dbd5660da2cb66c24471c7d5ec8c8427c0407bb9' 
  AND token = 'LE/iOT1PfzTh+nb6wtwK0rpZvFZAP+kCjSwWYluOFFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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