SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7de53bac6524f72ab62adeab7cbbb4feff0452be6f373485d732f3e5370bbc29' 
  AND token = 'hqlEaNN+XHZgnjZqT+tWgbEbgl75fzAomGmvJJrpps0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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