SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba4ff48c31733a31dbe24d831cc2ea16e27588650cd3feffd94510aab66c9fae' 
  AND token = 'RJN3C43ob9MK9faxWB6uVIzbej5k1cRtwBm+wS5UtfE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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