SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3fb3d3b747faed7b87b1654caca826612ba45fe93134b56bb6a542a48b9e9e0' 
  AND token = 'ttpqBB3tvdZxRSIDkYZvxGXwQJb9ochDJilG9Huzip8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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