SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ada0700feb73b3529361c4ef87f2b543f02e17eca492b1946503db7a56c00641' 
  AND token = 'RkUJVhIWon4xE2w/66jlZaq6lA8njijCTYiFMvG6IpU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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