SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f6924088d1da9a6dde15ab0431d5c0a639f0cf992cfb9cf460990bf64c3d534' 
  AND token = 'HYoO6yCkk0OWt+mxQOrpYraCwr26Bx9ZV0FyMp45EbA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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