SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b926508e7cfd7f8605581bd14ac507d2ed2056abea1e4a04efc11787459eff7' 
  AND token = '3Egw4LYDKgOCpoOvWG3QEkn/KamXY1wkvjLPHoBFlPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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