SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1edbf1ccec4a4ac39218f4762c20fb6662e352ef060e337f7b36b42993deb84' 
  AND token = 'KBGU5VzU53lRsyZfdNyiK/gbljJ8n7kEemA4QYZfvzA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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