SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8059f1ee1fe559097f83dba9f444b0869d9873c73cfd98887f3adee5bfd31c75' 
  AND token = 'qNC7CXt0JmqsD1ocRzAlfz5tgdXVwyNe4rK/w74W6BE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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