SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc9b9847d6dd1535b563769a010e24cfa69f0b317267dca1d1eb0570854d476f' 
  AND token = 'qGNP8ag7sMzduzZL/M/EzjkhK8JfHydHtmhOZkHurpw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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