SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d89726ccc383599bade9c2e0953c9115853764d6b367e03154df7d572279f07' 
  AND token = 'KkP97ex4SQ2SkYN2AxYLL92IcibMw2gTKoQp0bzAS5A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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