SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8449e843080a17751b77bc015096af6764b225160b9c275434749b3567e649ba' 
  AND token = 'ZZrlpEkVlbGEoYVRKbVOe0RqT5nRtR9KSa8q+FOhc9w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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