SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00d88f8ba87e9234986b33a04af8caf03f8a2bd050f58458e490a177a078d7a4' 
  AND token = 'XZMkTIIMvQvN37PEk3sQutKsbygVMBz/YkMhzJqA3NI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}