SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '483355636f77f7149059c6cc0b20b077bd22eed9bc5e238503eccb1436331301' 
  AND token = 'HW3IO2KCaAjv+mGVHQvpr94muhepe+qCPvzD03ZiTF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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