SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7997523e3670dabf7793d89de7f2aa507062ee949a55fc5b72ede110e411765' 
  AND token = 'ho3Z/4sMrfjv1nrWsJDYzH7OYFBFBD4VbkjMt36mRps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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