SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdc9c0cc9c946891d3c249bb9a0ecf34484b9df99767da6f901ffccb140509ca' 
  AND token = 'hAwnvJ5L2Zv62hAJl0c1ymV0pO7RaWmlWBAvCDLwzKE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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