SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dba81ac457b4b008684173620c738acb19a4ee6c348414ac6fa1eb763002911b' 
  AND token = 'WoUia5Ye7Vxl3yKj4NOhyomRA+/xMcjCrb6AUYTbvPg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}