SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e2e90362489270b40c134faa36bb09cf38fd6df5c276d4254918e9ccc18e159' 
  AND token = 'wj4+YAVM/5YtxRK4nfQHyowS7ww7zZGLnlSJYqCcSDQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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