SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fe870bbc6a3ba4b315065c1473c287d810cfe149bf277b23e82a62d2db55db3' 
  AND token = 'BKLzoWxLqwgN6KQdxqb78YOGlPjHJFFrAhFqWM2nJ/Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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