SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '859784dbfe4c48fe1e6c0513b94a5490a50cdbf76ddd7500328ffcce6cf5c5b2' 
  AND token = '38mcXPVfW6p2GBdLhp5wYUmbzJuJzNQbxMDVior8ssk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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