SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddd847974ea1f61f16f60ab3d79a027e1fb4686638e72656415708005f83535c' 
  AND token = 'OAQAanaphxynwITGPT0g2jZYnFocbgQ2pwozJzF6gn8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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