SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0cae3f36edcba9a3f3bec8bf57d1ea4522e913114789f888ca4e487eee8cdf90' 
  AND token = '2YvYPbGQPwp4/nse2OTnIgqtfAYzpttm6zjxhLr3Q/w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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