SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '233e6b4644af0a4c6efa7d92030a4ddb6a09bde66060b3fc37605def61fbf0b7' 
  AND token = 'bsusKzEZLNujvpkrwGHv3nRcthhqgUlgORzb53mk+To=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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