SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65a420fbd5299131a400f7f73ebe23e4634aac19c0142153651d20189fcff2c0' 
  AND token = 'Jb+oWPdZaIRtvI5bfyuACnqyEmJsa8tFxq4bsp9yR9w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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