SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20fe5d86c3f95c80c1d3f8863372dd8a50219c3a0f462c21ef5b6573eb322e50' 
  AND token = 'NrcJa3t0PRNbwwd3GFqEe1Yvkkq9nlBtbXfPfO3RGLE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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