SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3bb2c7f12a734fb17d4585e97cebc959785077e07ef6064ae1cd1a4d903d31e6' 
  AND token = 'gGAIHUysRAY7jBhGjVShTpwMmOdoVf6CwRPFVB6Y72o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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