SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '732999602a4d6f69a4cc606c51f9798f30b9b3abf4992379e1df9c7e5acfcbfe' 
  AND token = 'UgK1v1rSTQqaEavd6NaYOYrLkAk3iRh8MIJajczbbx8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00011

JSON explain

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