SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ba75549e2f2e440fa48025dd04c15a9463a6605dd614b55dafb0abe1d14984b' 
  AND token = '/aWVYr0j1gDaTHgQvbKvfjVKfniIgskgT7XHbxYrsVg=' 
  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"
    }
  }
}