SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f5d7279fb9a630dfffa94b0629e81e4ff2eb58688f3c38a792719b352e84875' 
  AND token = 'ou8ITZMwaFLvWea6yEvNdjnqV9T1jJzX55LX7DDlPjw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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