SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb56ebfd93816c96101faa874aefb33659d2342a18b9c1196456bdf2bc0f604f' 
  AND token = '1LXSiIYDJN71IMgGEjg36Fxo3NvrnM2F1JZLk4F3gtc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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