SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52bdfd9ca198ae570bd2172949f9c56fd91d120640c48da2ea8566098370beb8' 
  AND token = 'mXYhO0SOVgvERGMzJprMVnn5LoNtNbTGPzV8KpYL7O0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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