SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '830018c694dc71eb7dbdc73e6dbad9a53df3119293a8c65934cab5e42cccc32e' 
  AND token = '2ngcVqFKs8Od/Y+kkZQ3qekGlAiXuVBWIdkYCNYXrEw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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