SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d4c69816ef284694771643a014e9b65abc0bb24736eb1f9760bf48395d658c1' 
  AND token = 'Z3NF0BucQiUiGfvReDfpOZKe6sl4SlXIbgAhz4+pJrQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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