SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96dd866110a01ea5887ecf27e0a4a8df226d09f1a2030c2bbeaff77f0db8b41b' 
  AND token = 'GZ78TlTrHiwStcFncjwd5KvzUl3dtH86D5UCAMTzWVE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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