SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47504fa552f6bbfa98d96b599950b5ceed67bad50f311eac615a11fbcf418e55' 
  AND token = 'Qhz5ilaNog9HaXHpWlwJOc8iiO+IiETSWRLXHQYQrek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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