SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d5539c8309a309ce55681f3dc4cc13f641d7896994c6a91e84bdd7eff26701d' 
  AND token = 'xqjKRJF/dLDHci7QHEHXq6pijhNzMGsyFm74ppurcyQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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