SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e919c3e901894b12c84753d9d3c2a575f03b4f2ef2706d6924af43552d1e7e9' 
  AND token = 'ITYywy8ue7tkeVKT4e2RlRV0CZNLWWvRJ+sB0WX88YY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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