SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9431ff54683d36b2ebb74f8df7641ba291a8ea5c83e5415a8321728ffbb36b2b' 
  AND token = 'GsjCzwUrIU9XfrhsWpBAGfnsWvpLeVlQ7fk6qy8RIoM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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