SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb83692251384aa59c6192a7afb2beff45fafcf3515c46b75af2f0ff56bc2871' 
  AND token = 'KDeRo5qlvBxopvkkVlGYu9Q3KZDCEYC6899bEIJWHNI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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