SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d06f66259870842ed5a9beb9af8aa05b8576132398d55db4f5e2dedde9e0c9f' 
  AND token = '+zDrHk86BvIYAhdFHu7HfTDlkIRl0cZr8v84RhClc50=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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