SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '76fd3568fc1a67b2015dd851724ba16183fc4055b1f417c15c6ace6ba897b934' 
  AND token = 'tOV1caTwqkGz14izNQaWLXOziV2VTnQadqb+ukdKqAI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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