SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70517f14792545188e45752abc5dac848a5f3e49743406f66139e9aa2fb474e6' 
  AND token = 'Fto7uffplOrMVqRpz4ZK9ZsdPSH7iXmE+WUQUihlo/8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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