SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39918b4dfe027a376fbf8e2314ad63ae5b9c384586703b4fd368e4594b72987d' 
  AND token = 'w4zCAEk7VL8yngzFuCfwgUL9ZjBpKTGRD3OG5XbC08s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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